I actually got rid of the XTI a while ago. I had two 40D's, which worked great, because I could mount the 17-55 to one and the 70-200 to the other. All the controls, the pictures, etc would be the same without having to swap lenses.
Jumped on the 7D when a good deal popped up on Craigslist. Currently trying to unload one of the 40D's that I have. So far the 7D is ridiculous! In a good way! Took a bunch of shots at ISO12800 today! It is almost like having night vision, haha. The video looks great, but I'm still learning in that regard. It's a pretty big step up from the 40D, IMO.
EDIT:
How do you like the 24-70? I went with the 17-55 and I love it, but I always wonder what I'm missing with the 24-70. You shoot on a crop body, right? I really don't think I could handle a 24mm wide end for normal work. It's just not wide enough for group shots or tight spaces. Plus I'm a huge fan of IS. Don't plan on buying any lenses without it! The 17-55 is probably my favorite lens, even over the 70-200 2.8 IS. It is REALLY useful in a lot of situation. It's tack sharp (way sharper than the 70-200) and focuses fast and accurately.
Only downside to the 17-55 is that it's built like crap, IMO. It's not terrible, but it's not L quality either. Feels about on par with the 17-85 or 28-135. Decently solid, but not built like a rock like the 24-70. Someday I might be tempted enough to try the 24-70, but for now I think I'm pretty set with the 17-55.