Re: dRebel vs. 10D - I think there are several reasons to choose the 10D over the rebel. The 10D probably won't be replaced until fall of this year, and even when that happens, it won't make the 10D any less of a camera, and the only upgrades you'll see are probably more MP and better AF performance. The dRebel has a few limitations placed on it in firmware - you can't do flash exposure compensation. Don't have custom functions, and are limited to only one AF mode. For most people, this isn't a huge deal. But if you're used to the flexibility of Canon EOS bodies, it will be an issue. A buddy of mine has a dRebel. It takes the same quality pics (same CCD as the 10D), and actually autofocuses better. However, he had to buy a more expensive flash(550ex rather than 420ex) to be able to set compensation. Last night he ran into limitations with the AF modes. Just something to consider.
A lot of people are still shooting using D30 and D60's. The D60 is actually better than the 10D in some respects. Just because a newer camera comes out doesn't mean the quality of your current camera lessens.
I do agree with Johnny - shooting digital does allow you to get lazy. But if you're serious about photography, you probably want to learn to get more "keepers", regardless of the medium. You can be just as lazy with film, it just costs more. The advantage digital brings is that your "mistakes" and the learning process doesn't cost as much.
For those bellydance photos I posted - I probably took 60-70 photos. I didn't shoot haphazardly, but I'm sure I shot more than I would have with film. However, I was able to periodically review my shots, adjust for incorrect assumptions or changes in the lighting while shooting a VERY active subject. If I were a better photographer, I'm sure I could do that without having to review. But in this case it allowed me to learn. I also had a decent number of slightly out of focus shots, b/c by the time I focused, recomposed, and shot, the dancer had moved a foot or two (or across the whole stage), when my DOF is at most one foot. Either way I would have learned my lesson (I need to shoot more events like this to hone my technique), but at least I walked away with what I would consider 5 great shots. And I have the EXIF data to review what settings I was using at the time, as keeping a notebook at an event like this would've been impossible.
The best learning tool is an all-manual film camera with a fixed 50mm lens. It will teach you about DOF, shutter speed, aperature, and composition. However, once you've learned to think in those terms, I think a digital SLR is a great next step up. It will allow you to get instantaneous feedback to hone your technique and not just learn what you did wrong, but also see how to do it right (by being able to try again immediately). If you truly are interested in learning, you will do so even if it's easy to shoot off 200 shots in 5 minutes. You can be just as lazy with a zoom lens - it doesn't require you to think about composition/framing as much. I think it all depends on where you're coming from
J