I just upgraded from an XTi to a T4i about a month ago. A couple of thoughts:
The 18-55 IS lens, while not STM, is still a good basic lens for photography. If you want an STM lens, the 40mm pancake is very affordable ($199), and I recommend it. It's great for both photo and video.
The touchscreen, while seeming gimmicky at first, is actually really, really useful. My first inclination was to disable it, but after actually using it, it's a brilliant addition, especially when shooting in live view from a low or high angle.
Finally - the big selling point for me over the T3i and the 60D is the improved live view focusing. I compared it with my cousin's 60D (which is the same as the T3i CMOS), and the T4i wins hands down.