See all those big white lenses at sporting events around the world? They all have Canon EOS-1D's hung on their hind ends.
Nikon's got some speed demons as well. Actually, even my 5DII, judged to be sluggish by today's DSLR standards, is pretty doggone fast. And my 7D comes very close to the speed of those 1-series Canons. It can also be seen with a big white lens attached from time to time. :-)