After playing both of them (for the Xbox 360) I have come to the conclusion that I enjoy NHL 2007 far more than 2k7...
2k7 feels a bit too arcadey for my liking, especially as check-centric as the game is... There is very little playing the puck in it, more just charge the player and take the loose puck... Not to say it doesnt have its strong suits, such as very smooth online play, and a much deeper franchise mode than 2007 has.
As much as I hate to say it, EA has done something right with the new control scheme of 2007... It did take a little getting used to, but after 3-4 games, it felt just as natural as any of the hockey games i have ever played... Also the graphics are gorgeous, noticably better than the 2k one... But most importantly, the game seems to take more of a sim approach to the game (a first for EA, I know) which I enjoy far more than 2k7's approach to the game...