I'm getting it this week and my friend is getting it this week too. About sales predictions, I'm not really sure. It looks like english reviewers loved it and rated it high, but here in France most of the websites rated it quite low (around 60-70%). They basically say that the game is not precise, too hard, and they don't manage to defend correctly. A few ones also don't like the fact that it plays differently and they're not used to it. Talk about dumb reviews...
So I'm not sure that PES fans (at least in France) will buy PES Wii, since those guys basically hate when a change is made to their game. And bad reviews won't help. Now I do think that word of mouth can do great things and the game could have huge legs.