The Canon 7D was released onto the world in the fall of 2009. Literally for 2½ year, it didn't have any competition. It took almost 3 years for Nikon to come up with something in almost the same league. What a fantastic camera! 18Mpx, a very complicated but flexible focusing system and a buffer of 15 images increased to 23 images with version 2 of the firmware (I never got the official 25 images) and 8 frames per second. With its 2 CPUs, the 7D felt lightning fast.
Fall 2013, Canon releases the 70D, with 20Mpx, 7 frames per second, and what looks like a subset of the 7D's AF system.