Nintendo has announced that Mario Sunshine will be released in North America on August 26. Mario Sunshine will be the first Nintendo GameCube game to feature Mario as the lead character. Specifics on gameplay mechanics--such as those involving the water cannon on Mario's back--have yet to be revealed, but in a recent interview with GameSpot, Nintendo designer Shigeru Miyamoto said, "...we see Mario Sunshine as being kind of a continuation and expansion of Mario 64. So while we're working with this idea of maintaining the same system and style of gameplay as Mario 64, the director is really trying to add new elements."
We'll have more on Mario Sunshine before its release.