What sports do you shoot? What conditions do you work in?
Having used a full frame camera several times, and now owning a 7D, I really want something like a 5DmkII or mkIII, but I expect I will keep the 7D for telephoto sport shots.
I am in photography purely for the hobby. I have strict rules when it comes to shooting that I am Never responsible for providing shots. Sure, I will come to your event and take photos on my own dime, but if you absolutely MUST have decent photos of the event, then you shell out and hire an actual photographer to do work as well. And I still very much want to always own at least two cameras.
Why do I want two cameras? Because I like photography. I don't get out and take photos nearly as much as I want, but if I go somewhere that is going to be important to me I sure don't want to be stuck with a single broken camera, and then say "Oh well, guess we'll do this once in a lifetime thing again month when I have this repaired."
I also have my old T3 on loan to a friend from university who loves photography, but hasn't yet been able to get her own.
Having two or three cameras is not something suitable only for professionals. Personally I expect in ten years to own at least a medium format film, large format film, and possibly a truck sized plate camera/mobile darkroom.
So here is the question to ask yourself: What will bring you more in your hobby/life? Selling the camera now for something else, or keeping it and continuing to use it?
Canon EOS 7D | EF 28 f/1.8 | EF 85 f/1.8 | EF 70-200 f/4L | EF-S 17-55 | Sigma 150-500
Flickr: Real-Luckless