What? No Wii list Bod? That's not very fair. 
From a sales standpoint Wii Fit, SSBB, and Mario Kart Wii far topple the other lists. From a hardcore gamer standpoint, the PS3 is delivering the most sequels to the most major industry franchises.
If we wanted to divide franchise importance by sales history of the titles, the top 10 biggest exclusives this year would go something like this:
1) Wii Fit
2) GT5
3) Mario Kart Wii
4) Super Smash Bros. Brawl
5) Gears of War 2
6) Metal Gear Solid 4
7) Fable 2
8) Resistance 2
9) Killzone 2
10) Ninja Gaiden 2
Of course, some games should easily outperform their predecessors (Mario Kart, Brawl, Killzone) while others will most likely significantly under-perform theirs (GT5). Still, this isn't a bad rough image of how big each console's game library is this year. It's surprisingly much more balanced than you would think. 3 for Wii, 3 for 360, and 4 for PS3. Wii has the biggest sales titles, but overall fairly equal distribution.
And no, I didn't include 360 games that have PC versions with simultaneous releases (Left 4 Dead, APB), games that most likely won't be big sellers and are new IPs anyway (Too Human, Little Big Planet), or GTAIV for just it's exclusive content. These are just my estimates of the 10 biggest games.
Edit: FFXIII isn't even in the running for an 08 release. It's been repeatedly said it won't be out till holiday 08 for Japan at the earliest.
