Aaden: What the CE is missing, is a couple of papercrafts (you get the normal PE ones (= Geralt + random) plus the Draug - so you lack all the 'random' papercrafts but one), some bonus tracks (3?) from the soundtrack and, apparently, a couple of wallpapers and avatars. That's it, I think.
dnna: That sounds about right. There are 4 GoG bonus tracks, but you can easily find those on youtube. There are a few videos that aren't included with CE, but then again... youtube and/or gametrailers have it all.
I bought the standard boxed edition ( $49.99 USD ). I was surprised at what was packed in that thing. I got the coin, paper,crafts, game guide, Bonus DVD with a bunch of stuff on it such as the developers Diary, and cut scenes, and some other things that I haven't checked out, such as Vergan by Night. Another disk with the soundtrack, plus map & coin. I thought that was quite a bit for just the Standard Game purchase.