Tried out the Skate 3 demo too, and IMO it is a much needed improvement over its predecessors. On foot controls is MUCH better given it's very responsive and you actually run fast. Some of the new tricks are pretty cool and unique, like darkslides and underflips. Also tried out the Hardcore mode, and the most significant differences IMO was that you don't skate as fast and the game doesn't help you out with getting onto rails and ledges as much for grinding.
Really looking forward to its release, seems really promising.