Xbox 360: 14 million
PS3: 14 million
Wii: 7.5 million
I'm thinking 360 and PS3 are going to be extremely close next year, with a similar situation to what we saw this year (PS3 goes significantly ahead for the first 9 months, with the 360 significantly catching up during the holiday season).
It really depends when the WiiU releases, but I think the Wii is going to have very poor sales compared to the HD consoles. With another massive holiday season this year, as well as decent sales throughout next year, I have a hard time seeing the Wii doing much of anything next holiday season when so many people already have a Wii, not to mention the WiiU being released for the holiday season sales (as well as potentially more price cuts making the HD consoles even MORE affordable, hence being even better competition to the Wii)
Money can't buy happiness. Just video games, which make me happy.