A small leaked packshot from Sonic & Sega All-Stars Racing at Sega.com (as spotted by TSSZ) reveals that the Xbox 360 version of Sonic & Sega All-Stars Racing will feature none other than Rare's platforming duo Banjo and Kazooie.
It appears that only the Xbox 360 version will feature guest stars as neither the PS3 nor the Wii packshots reveal any additional characters.