To add to the comments already made here, chosing a camera body really is the least of your worries. As digital SLRs tend to date very quickly, you should really be thinking more about what lenses you'd like to own in the future, as they could well last you for SUBSTANTIALLY longer.
Unfortunately I don't know much about Nikon lenses, but can comment that both Nikon and Canon lenses tend to hold their value quite well and there is certainly a wide choice for each lens system.
Ref the bodies, go handle one in a shop to see which you prefer.