I have payment problems on GOG.com with my Visa card but it works fine on Steam. I was wondering if buying Witcher 1 & 2 from Steam and then availing the backup here would work or not.

PS : As of this writing the steam store page for Witcher 1 says that they are out of CD-keys and the keys will be given out as soon as they get them from the publishers.

Thanks for the response. I am aware of that page. I would like to know if the steam editions are redeemable there or not.

Yes, I did this with my copy of The Witcher from Steam.

YES!

Weird, I just did this now with my copy of the Witcher 2 but it didn't work with Witcher 1.

Steam had an issue with The Witcher 1 during the weekend due to the unexpected numbers of sales for that game, and there were a lack of keys for the past 2 days. Now the new keys seem to be not working on GOG.com, so my suggestion is to wait until Monday (next working day) to try again, or maybe later. But the CD-Keys from Steam indeed register on GOG for a DRM-Free backup of the game, that's for sure ;)

I bought the game in December 2012, am I still affected by this?

Probably, is you just recently (in the past 2 days) clicked on the CD-Key link in the Steam client to get one key for the game (for the first time).

You're right, that's the case. Thank you.

Thank you for all the responses. I'll go ahead and purchase it on steam =)