I think Geralt's abilities and weapons were upgraded for the demo, hence the Igni's/Yrden's huge area of effect, shooting three bolts, etc.
As for the overall combat, I think it looked cool, more wicked and agile. The fights seemed a lot more witchery than in TW2. I like the new effects for the signs, heck I even liked when Geralt shot the Gryphon in the face with the C.bow when it was about to dive on him. Of course, how the combat plays, that's a different matter...we'll only know once we have tried it out ourselves.
On a side note: I was thinking about a flashy (maybe even silly) kind of finsiher. Now that we can blow Aard continously, it would be cool to hold back an enemy with it, and while he was trying to crawl closer, we would suddenly release the sign and the he'd 'fall on' Geralt's sword (or maybe just simply on the ground). Geralt used this against the Striga in TW1's intro.
Dragon Age : Inqusition with it's different body parts attacks when it comes to dragons is something very nice and I was pleasantly suprised.I just expected.....more from Witcher (when it comes to gameplay,everything else blew me away but gameplay is half of game).
I kind of agree, what's there (and what we've seen) looks good, but it might turn out to be boring if we have to do it for 100+ hours throughout the game. That 'vulnerable body part' system would have probably made TW3 a better game, but it would've also increase the time and costs of the development significantly, so we could only play the game in 2016 at earliest (or not at all).