According to CTW, Core, Gremlin, Infogrames, and Rage have all thrown their hands in to support Sega's Dreamcast machine.
The presence of Core doesn't mean that Lara Croft's dynamic polygons will grace the system anytime soon. She's still got an exclusive contract with Sony, which doesn't run out until a few months after the Dreamcast is supposed to launch in the US. But reportedly the company does have a total of four Dreamcast projects - one exclusive to the system.
Rage's PowerVR title Incoming will make an appearance on the system, possibly in time for a '98 release in Japan.
Infogrames will bring Outcast, Alone in the Dark 4, a racing title, and another yet-unnamed game to the system in time for the system's launch in Europe. Gremlin is planning new versions of its Actua Soccer and Golf titles for the system as well.