Let me add something here: you have to be careful when buying gear - a DSLR is NOT a magic point and shoot camera. Lenses, flashes, tripods etc. are also potentially important. The key is to buy the components that will help your actual photography and not pay for those that don't. If you're not going to be doing a lot of sports/birds in flight shooting I wouldn't worry a bit about performance difference in AF between the various cameras. And, guess what? If you ARE going to be doing a lot of that type of photography, the lenses are just as important. If you're using cheap $200 lenses for sports/BIF you're going to have issues anyway.
So, in a lot of instances, a lowly rebel camera with better lens will help you make better photos than a 60d with kit lens. Certainly true when you get to flash work - a rebel with external flash is better than 60d or 7d with built-in flash.
So, before we try to sell our favorite canon model to you, let's take a step back and talk about what types of photography you're interested in. What do you want to improve upon that your current camera is letting you down?