Yup, 20 characters:
source: HERE (good read too!)Kukino confirmed that there will be a total of 20 characters in KOFXII, 11 of which are playable in the AM Show build: Kyo, Terry, Ryo, Ash, Robert, Kim, Ralf, Shen-wu, Benimaru, Leona, and Athena. KOFXII is currently 60 percent complete in development, and there will be beta tests before the game's proper release.