6mp is more than sufficent for 90% of photographers (including pros). Buying the body is just the begining of your financial commitment. Since you're new to DSLR, you're in luck cos you're not held back by existing equipment compatibility; so you're free to choose to build any system (Canon/Pentax/Nikon/etc) from scratch.
First thing to do is go check out the different systems from the shops or borrow from friends to find out which is most comfortable in your hands & how easy you can operate it. The last thing you'd want it to hate the system you just paid a fortune for.