It's too soon to tell if it's really "worth" the upgrade (Vary subjective and will be different for everone).
Hardware improvements are a few more mega-pixels (slightly improved resolution), Wifi (if you use the feature), 7fps instead of 4fps(T2i) (That's a nice improvement). 19 point AF - (Nice improvement).
However, with those hardware improvements, there are still a lot of questions to be answered about image quality, high ISO noise handling (higher density sensor), and dynamic range.
So I guess if you're flat out looking for better FPS, slightly higher resolution, and a little better AF, then this camera might be for you. To me the problems going to be the $$$$, because we all know Canon wants top dollar for the new gear. It has to make folks wonder if those incremental improvements will be worth it.