Hehe, I was just about to make a new thread about the demo...
Well, my first expressions are overall positive - even though there are still some things that bother me, but those are minor problems (yes, the mysterious absence of the refs is still there)
Weather is amazing - it looks brilliant the way players get wet and dirty, and their kits and hair get soaked as well - amazing detail!
The stadium looks alright, but it just seems like a boring stadium look-wise, I believe it's the Wankdorf Stadium.
The atmosphere is great too, with the crowd going totally nuts before, under, after the match and
especially after a goal, throwing confetti and stuff at the pitch.
A nice touch is that you're now able to do your own celebration. By moving the analog stick in different directions and pushing the triggers simultaneously, you get different celebration responses - a fun detail, but I still think that the real celebration scenes are still way too short.
The passing has been fine-tuned a lot I think. There are power meters for passes, through passes, lobs and shots. These work great IMO - shooting is a lot better than FIFA 08, passing around is a joy (especially without the assistance) and overall the gameplay is just way smoother than FIFA 08.
You should definitely go download now, see for yourself