For the most part it is a good idea. I don't like the name change though, the 2k series was a recognizable name, now they're basically pushing themselves back to square 1. The average gamer out there is not going to have any idea that these games are even mildly tied to the 2k series. And the fact that most people buy games (especially sports games) on name recognition (Madden anyone?) puts SEGA at a much larger disadvantage than they were at before.
They should've of went with something more along the lines of SEGA & ESPN presents: NFL2K4.
EA do use 2002, 2003 etc for a lot of their sports games so it might end up being less confusing in the long run. It'd be an easy mistake for someone to go out intending to buy NHL 2k3 and come home with NHL 2003.