This is going to sell for something like $250 less than the D300. Nikon and Canon seem to try, for the most part, to line up their cameras so they don't compete/compare too directly - so the 50D is going to have a few trade-offs when compared to the D300. Canon also seems to be very careful about separating their higher-end cameras' feature sets from their lower-end ones.
The number of AF points isn't a big deal for most photography IMHO.