Good summary Trestres.
Although I think the PS3 has a much improved line up over previous years, and finally has a more appealing (to the Japanese market) hardware design, I still think Nintendo have the advantage here. Wii Fit Plus may invigorate sales (though it will not have the massive effect the original did) and will add some strength to weekly sales in the long run. I genuinely think NSMB Wii is the game to push the Wii in Japan and worldwide-I think Nintendo have (at least) a massive marketing campaign planned for this game, and possible hardware bundles.
Wii will come out on top, but not by a massive margin. FFXIII is the game that will push PS3 close to Wii for the period. Even if it just has a massive opening week, it'll push it close to Wii's overall sales for the few months. In terms of home consoles, it will definitely be the most competitive period in Japan for quite some time.