Amazon usually knows before anyone else: http://www.amazon.com/Two-Worlds-2-Pc/dp/B0016O5G30/ref=sr_1_22?s=STORE&ie=UTF8&qid=1283201261&sr=1-22
Probably a good thing, considering Gothic 4, Fallout New Vegas and Fable 3 are all coming around the same time.

My birthday! I really enjoyed the original Two Worlds, so I'll probably end up picking this one up at some time or the other (probably not at full price though...)
Amazon says it can save me 17 cents off the RRP. Thanks Amazon, but I'm not impressed.

Good. It will give me time to play the first one and judge whether or not I want to grab the sequel.

The first one is very rough around the edges but the second one has been praised in every preview out there as a massive improvement.
Plus it has velociraptors.

Its not Gothic 4
EDIT: Nvm I guess they're calling it that now.

Are the expansions for the first one worth buying it from gog?

I don't think they're expansions are they? I think they're just more maps for the abandoned multiplayer mode.

If you get the first one, make sure you get the Epic Edition which has all the patches and expansion packs.
The expansion packs mainly add things to the multiplayer part of the game, I don't know what exactly since I never tried that part.
The Epic Edition fixes most if not all of the bugs.
The game is absolutely great, I finished it within a week I got it, playing many hours each day. It IS a love or hate game.
One thing you are not ready for is how bad the voices are. You think that surely they are joking.
They are not. The good thing is after the first 10 hours, you get used to them and by the end, you like them.
There is nothing stopping you from almost going for the end of the game, although you will get your ass kicked. There are no invisible walls or missions which will stop you from doing so. I suggest you focus on side missions and exploring before you do so (main mission = related with your sister).
One nice thing is that there are different factions and you can choose who to work for, depending on it the world will change. For example, don't read this if you don't want any spoilers,
you can choose to play some missions regarding the defense of a besieged city, or not. If you don't and the city falls, the whole city becomes a city for the other side etc.

I liked the first one, despite the fact that it had some flaws. The biggest one, for me, was the combat system: they implemented a very good idea that was also its doom!
Let me explain: you can do a backstep to avoid being hit by your opponent. It's very nice because it adds to the tactical depth of the game.
The flaw of the system is that, the AI of the enemies is not very good, so if you get your timing well (and it's very easy to do), you're nearly untouchable, even from much higher-level opponents (I tried it). The only problem you can encounter is magic users and foes with ranged attacks. But if you're smart enough, you can avoid them.
Except that, it's a very nice open-world game, with all the pros and cons of an open-world game. Personnally I like it very much. I got to play just a part of it (bought it very late in the GOTY edition) before Mass Effect, then Dragon Age Origins, then Mass Effect 2 got released, so I had no chance to finish it.
Now that I know the 2 will be released and massively improved, I've just started playing it again, with the intention to finish it before the 2 get released. ^_^

Aw crap I have this pre-ordered. The German Royal Edition anyway (which said to have the English, French, etc. as languages as well)