Got this from Gamespot forum so credit to the guy. I also found this but didn't realize until now that it was punch at Assassin creed lol

In the area where you have to take over the balista if you explore you'll find a dead guy where clothes similar to Altairs from Assassins Creed in a broken haycart. And Geralt says something like "They'll never learn"

http://img834.imageshack.us/img834/5412/witcher2201105170515567.jpg

old.

There's another one in the journal entry of the Prologue quest "Blood of His Blood":

Had Geralt been, say, a potter, only charred corpses and possibly some earthenware shards would have remained. But the dragon was up against a witcher (...)

a nice sting at that harry potter brat.... :)

I didn't take that as a Harry Potter reference, and instead just took it as Dandelion being ridiculous in his story telling. Reading it definitely made me laugh though.

One of the guards in the Kaedweni camp, I think it's actually out in the Blue Stripes section in the outskirts, sings a really, really naughty version of the Sesame Street theme.