I personally think of Paper Mario as IS's way of playing around with the RPG formula. Having experimented with the Sticker option in Sticker Star, they'll likely go back to a more successful formula that sold better on the GameCube and Wii.
That said, I'm not sure if Sticker Star 2 is something that should be feared. Bear in mind that it was essentially a prototype for a new kind of RPG, and also bear in mind that Thousand Year Door is considered a big step above the original Paper Mario. If Sticker Star 2 were to come out for the Wii U or whatever, I suspect it would be all about refining an original and worthy idea. The resulting game would likely have a better story, more content, and better balancing than the original.
Love and tolerate.
