the 60D with a 70-200 4.0.. Which I happen to be selling both
but yea, the 60D has more cross type focusing points, it's still not the most accurate body on the planet when it comes to auto focus though. you're probably fine with a rebel body, but on a lens like the 70-200, only pro bodies will make full use of how fast the AF is. After shooting on pro bodies, and on xxD bodies/rebel bodies, I do notice a difference, however, I feel that I'm capable of taking a decent image with a rebel body, so I don't believe it's the gear that will make or break the shot.
All in all, you're fine for right now with the t3/t3i or what ever rebel body you're looking to get. If you don't plan on doing any video, the 70-200 2.8 is a great lens to own, and will be great for when you do decide to upgrade to maybe a 7D, or a pro body.