The Witcher 2: AoK EE is DRM free and you get the same bonus content like in GOG version, and I thought it's the same with The Witcher: EE DC because CD Projekt RED are DRM free guys. I installed it, and no, it has Steam DRM. What is funnier, game has all the bonus content like GOG version (it's even written on Store's page), but they didn't striped out Steam DRM. I'll try exe from GOG version and report it. I don't have The Witcher 2 yet, but for DRM, read this: https://web.archive.org/web/20141207165227/http://forums.steampowered.com/forums/showpost.php?p=32128446&postcount=5
Topic on Talk:The big list of DRM-free games on Steam
You might want to contact CD Projekt RED, I think they'd be more than willing to remove the DRM. Then again, they may have done it because they wanted the GOG version to be the only fully DRM-free one.
Good proposal. Will contact them in the following days and will link wiki pages. For The Witcher GOG .exe, we'll have to wait. Download is almost 10 GB big, and I have some other games to test first but it will be in a day or two.