How Many Megapixels?
Most cameras today come with 10+ megapixel sensors. For most applications this is plenty. Too many megapixels can degrade the image if they are bunched together too tightly. Simply looking at the number of megapixels a camera has doesn't give you the complete story, though. Point-and-Shoot cameras (P&S) have very small sensors and so the more megapixels crammed into these sensors, the more heat and thus noise each pixel generates. This means the image becomes noisy. The Nikon D700 comes with a full frame sensor and 12 megapixels. This means it handles noise far better than a similar camera with a smaller sensor.
It's All About the Glass
Most professionals will tell you that the camera is not the most important tool. Don't get me wrong, a good camera is a vital piece of kit but I see a lot of people wandering around with $4000 cameras using lenses that are effectively coke bottles. To be honest, I would much prefer to have a cheaper camera and get the best lenses money can buy. The glass can limit you as a photographer. Spend more money on glass and suddenly you can shoot in much lower light at much faster shutter speeds. If you're looking for good glass at a reasonable rate, check out Sigma's EX range of lenses.
The bottom line for me is that even the most basic of DSLRs today allow the photographer to shoot great images. Couple this with three outstanding lenses and you're good to go.