According to ign.com Lucasarts has cancelled the Dreamcast version on Super Bombad Racing. heres a quote:
Dreamcast owners who have been waiting for some kart racing action, Star Wars-style, may become angry with this tidbit... and we know where anger leads don't we? Star Wars: Super Bombad Racing has been canned for the Dreamcast, though Lucasarts is still planning to release the game on the PC and PS2 for a Spring/Summer release this year.
Source: ign.com