Paper Mario: Sticker Star is still on track for a fall release. This morning, Nintendo of America announced that the game will be released on November 11th in North America.
Sticker Star begins when an accident scatters stickers across the land and Mario sets out to repair the torn world. Unlike previous games, Sticker Star has no experience points. Instead, you search for stickers around the environment and use those to open new paths or as items in battle.
You can find the most recent trailer for Paper Mario: Sticker Star here.