This is, without a doubt, a day one purchase in my book. I am a fan of the original Dead Space and I have certainly been looking forward to the sequel for sometime. Well I went over to my friend's house yesterday and he had the demo. And let me just say that this is certainly worthy of being Game of the Year material already. Arkham City better watch its back :P. If you don't already have the demo, please download it immediately. But if you can't, try to find it on Youtube at least. The controls were silky smooth, the graphics look amazing, the atmosphere is just as horrifying, if not more (it made me jump a few times :P). The death sequences are absolutely brutal as well (one special notion goes to the church in the demo). I certainly think that this is going to top the first game indefinitely, provided of course they change the mission variety (which was the biggest issue that I had with the game).
Well, those are my thoughts on the DS2 demo. Do check it out.