NHL 07 is the biggest letdown the series could ever offer.
NHL 06 just updated its roster. NHL 07 does so, but it is not enough. How can you release a series if there is no improvement in its games from year to year. The gameplay and graphics are the same since I remember myself playing hockey. What I said in my review for NHL 06 is correct for 07, too. Of course that doesn't mean that the game is bad. On the contrary, the gameplay will be difficult to understand for the newcomers, but the older players will enjoy it pretty well.
If something is improved a bit, that is the skill stick, which van be used wiser than it was last year. And I am also grateful that the player figures are somewhat detailed this year. But the graphics face the biggest decline. They are decreased a bit for the sake of a great performance, which also lacks on condition that your PC is not updated with the latest parts and drivers. All the rest remain the same.
Of course there is still a reson to play NHL 07: if you have a powerful system and a previous experience with the series you will have a really good time. If not, I reccomend you to rent it first to see what's going on with this game.