Sounds to me like you should take a look at Olympus.
The new E-3 has an extremely fast AF system, crop factor of 2x (which makes a 300mm f/2.8 into a 600mm f/2.8!) and shoots 5fps, which isn't remarkable but OK for sports. $1,100 bucks for the house and another $2,000 for a 35mm-100mm f/2 (70mm-200mm f/2.8 equivalent but half a stop faster and half the physical size!)
I'm an all-Nikon shooter myself, so I have no personal experience with the Olympus system, but from what you described about your needs it seems like a good match. Check it out!
