Well here's a comparison with the beginnings of Uncharted, LittleBigPlanet, and Brain Training so far.
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Looks like LittleBigPlanet launched better than either of those due to its enormous hype campaign. But it also looks like it's tapering off faster. Uncharted (thanks to some bundles) had a slow but steady clime to almost 2 million after a whole year. Brain Training is a Nintendo game so it has legs that reach to the moon and it's at 14.6 million and climbing. It's highly doubtful that LittleBigPlanet's better launch will translate to sales higher than 14 million, let alone 2. We'll see. This could be the PS3's Viva Piñata: it doesn't sell too well, but it becomes a beloved franchise with sequels on the DS.
EDIT: It seems LBP has bundling, and Brain Training did eventually get bundling, but that was years after it was already super successful.
