The Nikon won't take Canon's telephoto lenses, the ones so beloved of Sports Photographers, if the sidelines of every major sporting event are to be believed.
You say they have 3 D2H's, and so likely lenses for them too. Given that these lenses are on the expensive side, the fact getting your own Nikon would let you use them might be the most important thing for you to think about. There may also be some value to their Nikon experience.