I think Mata is more versatile than Kagawa, and certainly more acclimatised to the English game. Twice player of the season at Chelsea is nothing to turn your nose up at, and we do need a quality winger and a consistently creative midfielder which is something he can cover both of. Would still like to see an amazing central midfielder but I actually agree with Moyes that if they simply aren't available right now then we shouldn't rush anything through.
My only concern with Mata is that it seems he is frustrated at a lack of first team opportunities and I always question when we buy someone because they can't get a game elsewhere. It becomes a question of whether we are looking for not the top players but the next level down. Still, I think Mata being 25 years old with two player of the seasons in the bag for Chelsea means that he's not "lost it" just yet.
I still would like to see some other signings than Mata, but I can accept that sometimes these things just aren't that simple, particularly during the January transfer window and particularly when many are cup tied in UEFA and many are simply wanting to wait and see where United end up after 38 games.
I can see Chelsea simply shrugging and saying "no" throughout this transfer window at the very least, though.
EDIT: In other news, 6-8 weeks out for Lucas is a massive blow for Liverpool considering how they struggled without him in the recent Villa game, he really turned them around. In other other news, Mancini gives a massive gift to headline writers around the world as he writes everything but "on Rock and Roll" out for them.
