The first expansion pack for Will Wright's "everything sim," Spore, is slated for release this spring, according to -- of all things -- an invitation to its debut event. Called Spore Galactic Adventures, the pack is evidently just one part of an entire line-up of Spore tie-ins/spin-offs EA and Maxis are planning for 2009.
Judging by its title, the pack will expand on Spore's galactic end-game, widely considered to be the sim's most engaging stage. As for what those other Spore titles could be, we'll take your suggestions (sorry, we've already called Spore: ODST!) in comments.