I think LBP will sell just fine. Unlike Okami, it is being advertised. Heavily. It's already being included in ps3 TV adverts, and they have signs up in every GameStop saying, "The Best Games are on PlayStation 3," signs that show five games: GTAIV, MGS4, GT5P, Resistance 2, and LBP, with LBP being dead center. Sony has often mentioned it as being their big holiday release alongside Resistance, and it will be marketed as such.
Advertising alone should be able to push it past a million, as it should sell to the same crowd that bought Ratchet & Clank, if nothing else, but the fact that every person that's actually played the game seems to be in love with it leads me to believe that there will be strong word of mouth surrounding this title, much like Uncharted. Even if it starts off somewhat slow, word of mouth and user generated content will give it very long legs, imo.
As for a game I think won't sell so well: Viva Pinata 2. The original only sold so well because it was bundled for a while, and Banjo will trump VP2 this holiday.
Though I suppose that wouldn't be considered a AAA title...
