in the 80's Nikon (who was the supreme leader of SLR cameras) did not take Canon AF lenses seriously and it paid very dearly by losing its top position to Canon and has not caught up ever since.
Oh, don't know about hasn't caught up since. I used nikons in the early 2000's, didn't care then but oh yeah, they were loosing badly. Now? Well they've already lost a chunk of the market which hasn't as of yet returned (if ever) but yes they HAVE caught up.
Damn, I just defended nikon! Sorry about that, but I thought it needed to be said. Doesn't matter what you shoot on nowdays, either make fantastic images, particularly in capable hands.