Don't hold your breath on Nikon. Aside from the usual un-informed prognosticating over at the DPReview forums, I doubt Nikon's going to be going full-frame for anything but a full-professional body (ie, a "D3" body), and even that's a way off. There's no good reason for Nikon to switch right now. No one's going to question the image quality of a D2X with pro-level glass on the front, whether DX or a full-frame lens.

As a serious photographer, if you want something better, you're going to shoot with one of those 30MP+ digital medium-format backs, as opposed to investing in a parallel Canon system.

I've got a D70s with the 18-200VR lens, and it's a great kit. It's a good jack-of-all-trades lens - it's not going to be a knockout tele like the $1500 70-200VR, but it's a great travel lens, can do acceptable macro work, etc. I've got a 50/1.8, but that gets far less use.