I think Nintendo understands the importance of Europe as well, and I think that is why they saved Mario Strikers for them. It will be a big game in Europe, and I wouldn't be suprised if Wii Sports has some sort of mini Soccer game in it. Perhaps a Shootout or something.
As for Microsoft, I believe they will easily win the US. Microsoft is a name that many people in the US trust for computer related electronics. They are geared towards making more American focused games, and have pushed to secure the best relationship with EA possible. And with their headstart Sony is going to be playing massive catchup, and is doing so with a launch with pathetic number of units available for this market.
Japan is easily going to Nintendo. Nintendo has designed a console that fits all of Japanese sensitivities. It is small, doubles as an additional player for most of your classic games via download, uses Wifi for online play, is a very cheap new console, and finally: introduces brand new and compelling ways to play games. I really see Wii vs PS3 being the exact same as the DS and PSP battle (EDITTED FOR MY STUPIDITY.)
I really don't know about the European market. How important is price, what type of games do they like, and so forth. I believe it really could be open to all the companies to win that market. But I am thinking that Nintendo has done a great job there with the DS Lite, hopefully they will continue that trend for the Wii.