A dude by the name of MegaVolt85 has been converting Atomiswave arcade games to Dreamcast disc images. Because the hardware is nearly identical (the arcade board has more RAM, but that's really it), these games are not ports, they're conversions that are running the original code natively. So far, we've got Metal Slug 6 (damn that game is stingy with ammo for special weapons), King of Fighters XI, and Neo-Geo Battle Coliseum. But he's said he plans to do all of them, which has me very hype for Dolphin Blue. I won't share links here, since I think that's still a no-no on this forum, but I've tried Metal Slug 6 on my GDEmu and it works great!