Wii is only going to get better (maybe not pure sales-wise) this coming year, there's a lot of great games coming out throughout 2008.
What I'm really curious about is the PS3. They have a lot of great stuff coming out in the coming year, and there's a lot of 360/PS3 dual release games. If they end up with similar prices (which they already sort of are), and a pretty equal stock of good games (which they might by next year), and PC hardware prices keep going down and more DX10 games come out (which they will), the 360's emphasis on FPS compounded with continued hardware problems may end up shooting them in the foot.
This holiday season doesn't interest me as much, as the Wii is pretty much the shoe-in for winning the holiday season, 360 will be in 2nd with a huge stock of great games in the last few months.
What will be interesting is next year, especially if a lot of these upcoming PS3 games end up being really good. By the of 2008 we could see a huge shift from the 360 to the PS3.
3rd Party Wall of Shame
http://www.nintendoworldreport.com/forums/index.php?topic=30478.msg581036#msg581036