I'm jumping to dSLR, what camera?

Hi everybody. I currently own a Canon G9. I feel it's time to go to the next step of dSLR photogrpaphy. Should I first try an entry level camera like the Canon Rebel T2i or should I directly go for a top of the line camera like the Nikon D700? What's the point of starting with a camera like the T2i if I can afford the D700 and start learning to shoot with it? Thanks for your suggestions.