Not that much different from NHL 06, but more fun nonetheless
There are also a few more modes in NHL 07 such as the shootout minigame and the Free4all. The only letdown of that mode is that you can only play with other human controlled players for that mode and not with CPU players. In addition to the shootout mode, there are also more leagues that you can join in the Dynasty mode (not just NHL). In Dynasty, you have to gain the owner's trust in order to get upgrades. EA has also added a salary cap like the real NHL and a new minor league system, making the mode more realistic.
To conclude, if you liked last year's game, you'll like this one even more. The graphics are slightly better, the gameplay is better, and there are upgrades in most of the modes that it comes with. The only bad thing is that the rosters are not completely up to date, so you will have to edit those yourselves.