I completely understand your concern.
I have been researching and thinking about getting a DSLR(Canon vs Nikon vs Olympus) for over 2 years now. Why so long you say? A little because I did not have the cash and a little of what you are saying. "Another newer one coming out soon - maybe I should wait?".
Well, always gonna be a newer one coming out soon. If you are not in the market then save up your dollars and then buy what you can afford and what is available at that time. Nothing wrong with the D50 at all. It just has a few less features and uses SD memory if I remember right. You can still get awesome pics out of that camera for sure!
I personally just bought a D70s body only and went with the 24-120 VR lense. I have not even got it yet! Suppose to be here by this Friday(And the wait is killing me!). Nothing wrong with the kit lense either. I just like the VR lenses and feel like this a flexible first lense for me.
If in fact, when Nikon comes out with a new version of the D70 or the D80 or whatever they call the new entry level version I will not sweat it at all. Now, when they come out with the D90 or 2 generations from now - maybe I will be in the market for a new body? Or maybe buying someone's D2X from this site? Hopefully, the lenses that I have at that time will still work on the new bodies? I am sure they will.
And just another thought to ponder. You are probably gonna end up spending a whole bunch more on lenses and other equipment. Let's see:
12-24 F2.8 something like $900, 70-200 VR $1450 or so, a good tripod and ballhead ummmm $300-600 or more, external flash $200-$300, and then there are the big zooms and other fast pro lenses. It never ends. Well, you can see the body @$900 suddenly becomes a smaller part of the big picture. Oh yeah, new computer and monitor, really nice home printer, usb or external hard drives for archiving etc.
And my last thought - I have seen people putting their D70's D100's for sale on this site as well as other photo sites. So if you are tight on cash, you may find a great deal here or in other photo sites. I personally have not bought anything used yet but, if I were going to buy some used stuff. I would definitely feel good about buying on this site as opposed to others or EBay. From what I can tell - here at Nikon Cafe there is very high percentage of HAPPY
Buyer and Sellers.
I have rambled on way to much. I hope this helps you a little bit.