I'll start with the striking animations in the game, which did not look all that great to be honest. Punches still seem to impact like feathers, lacking the devastation you would expect when they connect, and look almost identical to what we have seen in the past two UFC releases. The lack of any sort of weight behind strikes in the series has always really bothered me, and I wasn't overly impressed by the snippets of gameplay I saw.
Even worse than the hit animations was the reveal of the new submission system. Now when a submission is initiated an octagon appears on the screen. A red and blue area appears on the octagon that corresponds to each fighter's corner, and the player that initiated the submission must maneuver this colored zone around the octagon avoiding the defending player's attempts to cover the zone up. It's a bit ridiculous looking, and it's incredibly obtrusive.
On a positive note, player models and lighting look to be improved, and cuts looked to be a bit more dynamic versus the standard-over eye wound that was always in 2010.
UFC 3 is still a long ways out, so I am sure the build we witnessed was extremely early. Here's hoping THQ dumps in the necessary effort and polish that the series deserves.