If you have a camera you like its best to invest in glass rather than a new body. Bodies chance every 6 months, good glass doesn't deteriorate.
Ergonomics are important in camera choice. And so is lens availabilty. Sure Nikon and Canon have the most and best lenses available. But those are pro lenses, well above the 1K mark.
I was hanging to Nikon uintill i read about pentax. Pentax has been making lenses and camera's since 1919 and every lens past 1975 fits on bodies made today. Add to that lots of 20+ year old lenses are about 30 bucks and Pentax primes are some of the best on he market.
Yes, i'm biased :)