Bug,
You're going to get great photos as long as you use the camera right and have a good lense. Unfortunately, if a pro photographer stood next to you and took the exact same shots with a Canon 1D or other pro camera (we're talking $7000+ cameras here), it would be clear which camera took better and sharper pictures. It's like going from a $40k corvette (50D) to a $500k competition model porsche. Yea the corvette is a nice car with great performance, but it's not gonna win in a real race.
That said, only someone selling their photos or an absolute perfectionist would ever really care. Plus if you shoot in RAW format, post processing using software can dramatically improve image quality. One big place you'll want to use post processing is chromatic abberation and fringing. Almost all digital cameras show a purple fringe on line edges in certain circumstances. Better cameras and better lenses have less of a problem, but they all still have fringing. It's something you have to live with when you use a digital camera. The good news is that you can eliminate the fringing in software by post processing.
So basically take a bazilion shots, and the ones you like, spend an hour touching them up on your computer before printing/cropping/enlarging/whatever. That's the same whether it's a D50 or 1D.
If I needed a camera NOW, I'd probably get the D50. It's more than good enough, is priced pretty well, and it would be a great tool to learn how to use DSLR cameras. Then if I decided if I wanted to make a step up to a better Nikon, I could keep the lense and buy a better body like the D200 or one of their pro cameras. But I couldn't get much use from it right now so I'm going to wait a bit I think. Maybe they'll fix the problem with the D200 and once it's been on the market a bit, maybe the price will come down a bit too. I read that Canon's 20D replacement is due out 2Q 2006, and that will undoubtedly give the Nikon D200 some competition.