You really should get used to it. For years now in Linux you can't see how much free mem you have, because after few hours it'll show you 100% usage. Using improved memory management in Vista is a step in a right direction and hopefully Windows 7 will be able to manage as much resources as possible.

So, let's first start with a little history: I've been using Windows since the dark ages (3.11 for workgroups) , going through 95, 98, ME (although a short while) XP and Vista. Also have been a frequent user of Linux (Ubuntu, SuSe) and Solaris (OpenSolaris) with a tiny taste of Mac OS X.
Now I've recently tested 7 on my C2D 7200 notebook running at 2GHz with 2GB RAM and a Ati Mobility Radeon x1400 and I was surprised; I was expecting a good OS based on the discussions on the ArsTechnica forum but at first I didn't think that the new taskbar will work for me (my biggest concern). Turns out that the work they did is great compared to prior OS betas and that they appear to have respected the oaths they took (less system resources consumed, better hardware management, less intrusive UAC etc.).
They might have copied some things from OS X such as the behavior of the taskbar which looks more like a dock now but that turned out to be a good thing at least in my usage patterns (many windows of the same app open at the same time, live preview for media playback etc.) as well as the new 'quicklaunch' system implementation based on the average time the app stayed running and the number of calls to it during a session.
What I don't like as much are the libraries and the fact that opening computer goes to them instead of the drives in the system. I loved the saved search options in Vista (don't recall their names now, been using XP due to some dated software) and they work as well in 7... now if only they would be a way to dynamically modify the criteria after the search has been saved.
Driver support and compatibility with my software has been so far great and the system is snappier than under Vista SP1 during routine activities. I'll get some time to post some screenshots sometime today I hope.
All in all I am impressed with the state of the OS so far.
Later edit with a small tip: In the taskbar, while hovering on an app, shift-click or middle-click to create a new instance. Left-click to switch to the same instance. Ctrl-click to cycle through all instances. This way you can for example create a new IE windows (or any other app from what I've seen)

What are you using to view your RAM usage? htop, top, free, etc. and any tools built on top of them should all separate occupied memory from buffers/caches, so theres no reason it should be showing you 100% usage unless one of your applications has a memory leak, or the GUI tool you're using doesn't display much information at all.

They don't, I mean they show cached memory separately, so it's like 2GiB total, 2GiB used, 400 MiB cached. If I remember correctly, windows doesn't show cached memory, so you only see two first values.
Besides, I may be mistaken, but I seem to remember a discussion on kernel-devel few years ago that said it's impossible to get an accurate number of free mem at any time.

Not impossible, but very very hard. The problem is that processes often request memory that they don't use, so modern OS only really reserve memory once it is accessed... which, naturally, produces a fine mess as the memory requested and granted by an application is not the same as the amount it uses. Add to that virtual memory and you can see how hard it is to determine the real memory usage.
Edit: Another thing is that many requests by applications really increase kernel and not application memory usage. This is one of the reasons why Internet Explorer's memory footprint still seems compatibly low, even when it loads dozens of images. This was really an issue for Firefox development: Should Firefox continue to make use of kernel memory for images, so that users would get comparable numbers to other browsers, or should it do the right thing and store images in it's own memory? In the end it was decided that it was better to do the right thing, than to keep the displayed memory usage low, but it was a tough call.

Does anybody know if the Window7 setup includes a partitioner that can resize partitions? Would be good to know in advance whether I'll have to prepare this myself or if I could just leave it to Win7.

Decided to try installing on an old Vista partition (that I had cleaned up, so there were no overlapping files).
Seems like there's light at the end of the tunnel: In contrast to Vista, 7 is working pretty well on my system. Not perfect, and there are still some irritations (Don't try to remove the Library from the Explorer, it will reappear each time), but there are many steps in the right direction.
Something that I would desperately urge Microsoft to do this time, is work with device manufacturers. Again, my gfx chip (GeForce 7900 GS) was not detected at all. Since Windows7 connect at install time to download updates, that would be the perfect time to also deliver newer drivers.
Aside from that, there are some very strange bugs (don't try to change permissions of files with very long name) and even stranger error messages ("A message was sent to the system which was too small" is what happens if you do), but nothing that could not be forgiven.
Under the hood there were only minor changes, some of them very, very helpful (fixed paths, like "Documents and Settings" are no longer redirected via Junctions, but instead at the API level), but many of Vista's irritations are still there (or got worse, now there's AppData/Local, AppData/Roaming AND AppData/RoamingLow, when there should be only one). But it works now for the most part. Placing of files is still a bit like roulette, but many times you will now end up with the desired result.
The new UI additions work, for the most part, perfectly. There are some minor bugs (dropping links onto the taskbar works sometimes, and sometimes the focus changes at strange moments), but if MS fixes them, 7 could be the release that Vista should have been.
As one of the Vista victims, I'd still urge Microsoft to make this a free upgrade for Vista users, if only to restore some of the trust it lost during the Vista debacle.

>>Microsoft
>>free
Does not compute.

Dang. False Alarm. The junctions are still there, I had simply missed the "Show Hidden Files" setting in my excitement. Also, seems Switcher, which is an absolute must-have for Vista, seems to have issues with startup and minimizing.

Damn, damn, damn, damn. That's why I say heuristics are bad idea to build an OS upon. Apparently, 7 thinks that MPlayer shouldn't be burdened with running Aero while it's playing a video in fullscreen. Apparently, MS thinks that every GL application running in fullscreen must be a game and should therefore get maximum performance, by disabling Aero. Problem is, reenabling Aero takes a moment, so I get an awful flicker every time a video ends. How do I get rid of that?

uninstall.
hahaha, just kidding!

Not yet... it still works pretty well, although I have to admit that such unpredictable behaviour was definitely a factor when I uninstalled Vista.
BTW, there's also a pretty big design flaw in the new taskbar... well big for me, others probably won't notice it. As icons and instances are merged in the new icon view, Microsoft assigned middle click to "open a new instance". Makes sense, since you cannot reach it any other way.
Problem is, that carries over to the standard taskbar view... where suddenly middle click means "new instance" too. But most other programs (Internet Explorer, Firefox) interpret middle click as "close", so I automatically middle click on the taskbar too, which has a totally undesired result.

Nice touch: The taskbar item for a copy operation also serves as a progress indicator. It's still noticeably slower than other OSs for small files (I'm just copying over my WindowsBlinds themes, which is about 400 MB in10000 files), but acceptable.

well if that's the case I don't think I'll move on.. my typical thing with every new computer is to transfer a ton of large files (game back ups, copying my large music collection, steam), and that is a real set back.

The effect seems to be pretty much limited to small files... probably a bottleneck in the communication between the interface and the backend, You should be fine for large files.
Edit: Taskbar Sguffle doesn't work anymore! The horror! The horror... At least you can middle-click the previews to close a window, but it's still not nearly as convenient as clicking the entry itself. WindowsBlinds doesn't work either: The start menu becomes an absolute mess... and Switcher has issues finding the mouse...