Whomever said 2008 was PS3's year got their consoles mixed up. It'll definitely be the year of the Wii. Mario Kart, SSBB, and Wii Fit will ensure Nintendo's console dominance for at least half of 2008, although we all know that these games will continue to sell superbly well into second half. I'm very much looking forward to seeing what they have cooked up for the holidays this year, but there's no doubt that they have another monster waiting to be unleashed on both casuals and hardcore gamers.
I don't suspect we'll see a steady stream of great third-party games on the Wii until 2009. Reggie himself said a while back that it would take 2-3 years for other developers to catch up. If this is true and Nintendo continues to pump out quality, fundamentally-sound, and FUN first-party games, then, I really don't see how the other two consoles will stop the Wii.