2K Sports just announced at E3 that their internal development studio PAM Development is working on a new installment in the Top Spin franchise. Top Spin 3 will be released in Spring 2008 for both Xbox 360 and Playstation 3. Top Spin 3 will feature some new gameplay mechanics, as well as the ability to modify your character.
Additional details on the game haven't been given, but 2K Sports did release the first three images of the game. Expect more details and media in the coming days.