C'mon guys. LBP will easily break a million. Hell, it should outsell Ratchet & Clank Future by quite a bit when all is said and done, and that game is already at 1.22 million. Sony is really the pushing the game as it's biggest exclusive this year next to (and from what I've seen, maybe even above) Resistance 2, and it will probably be one of, if not THE highest rated game this year (after GTAIV).
Loads of advertising + high critical acclaim = success.