I recommend downloading the demos of both. But based on last year's games, NHL 08 was the best sports game I had ever played 9and I didn't even follow hockey at the time) and NHL 2K8, while not terrible, was pretty mediocre. I'd go with EA's game.
Oh, apparently the online leagues of last year are gone completely in favor of the EASHL being the only online league mode. Can anyone confirm this? If so, do we have enough people interested to field a team?