The Dreamcast isn't dead. It's resting. The Sega console keeps getting new games thanks to homebrew developers like Redspotgames and NG:DEV.TEAM who continue to support the Dreamcast, years after Sega gave up.
According to these devs, the best part about developing Dreamcast titles is that you don't have to worry about getting a license for games and the game development tools are still fairly modern.
"The first time we asked for a license for a new game was in 2003, but Sega of Europe had no interest in new titles, and we could not release [games] officially," Redspotgames boss Max Scharl told website Gamasutra. "We tried a couple of times to do the same in Japan, but Sega of Japan does not give licenses out to non-Japanese developers or publishers—even though we have tried several times and even gave them a visit."
But Redspotgames continued to support Dreamcast after Sega no longer did. In 2007, Germany's Redspotgames released its first DC game, shoot 'em up Last Hope. Sega withdrew from the console business in 2001 and finally stopped supporting (and fixing) Dreamcasts in Japan in 2006.
Check out the rest of the Gamasutra piece for a long at what might not seem like the most profitable way to make games, but sure is the most passionate.