I think Ubisoft just realized that even released a month later, Red Steel 2 is competing directly with the multiplatform Bioshock 2 (which will probably slaughter it). And if that doesn't, you also have God of War III and Final Fantasy XIII releasing just a few weeks prior. It's a busy month, and it's likely that the audience that would buy Red Steel 2 probably has a pretty expensive February->March already. That is, of course, unless the mythical Wii expanded audience actually shows up to the party for once.
Of course, I'm not disregarding the possibility that the game sucks, either. This is an Ubisoft Wii title, after all.