DxOMark, which scientifically tests digital cameras, just finished testing the Canon Rebel T4i (also known as the EOS 650D). And it did not score well.
In fact, the T4i is currently ranked 93rd out of all digital cameras, which is really, really, really low for a new DSLR with an APS-C sized sensor. Compare that to the Pentax K-5 (ranked 11th) and Nikon D3200 (ranked 12th), the two top digital cameras with an APS-C sized sensor. The K-5 will run you a couple hundred more than the T4i and the D3200 will run you a couple hundred less, which means they're competing head-to-head. The T4i just does not hold up in comparison.
The Canon T3i, T2i and even the T1i outscore the T4i. Yikes! Canon took a step backwards in image quality with their latest release.
Now the good news. Even though you can get better image quality out of pretty much all digital cameras that have a similar price tag (and even some that cost significantly less), the T4i is still a capable photographic tool. And the even better news: the T4i may be the best DSLR for video, thanks to its continuous auto-focus, left and right microphones, and availability of "silent" lenses.
However, if you will not primarily be using the T4i for video, there really is no reason to buy it. There are plenty of better DSLRs out there. Heck, buy the T3i for less--it's a better camera than the T4i.