The Dreamcast died off long ago, but it would have lived a longer life if negotiations between Sega and Microsoft didn't fall apart.
The inevitable end of Sega's hardware business almost led to Xbox cross-compatiblity with Dreamcast games. Sega Chairman Isao Okawa was in negotiations with Microsoft to add Dreamcast functionality to the original Xbox console after it was clear that the Dreamcast wasn't cutting the mustard on its own.
The Dreamcast was first released in Japan at the end of 1998 (everywhere else in 1999), and regardless of its failure was a great console for the time. Modem support for online play was one of the Dreamcast's forward thinking features, and a selection of decent games were released for the system including Marvel vs. Capcom and the weird as hell Seaman.
The negotiations to keep the Dreamcast alive within the Xbox made it all the way to personal meetings between Okawa and Microsoft bigwig Bill Gates. As reported by Kotaku, former Microsoft executive Sam Furukawa tweeted: "Before Mr. Okawa passed away he visited Gates several times, to see if it would be possible to add Dreamcast compatibility into the Xbox." The reason it never happened was actually due to the Dreamcast's online features, which Okawa insisted must still be available through the Xbox. Microsoft did not agree, and only wanted Xbox games to have internet capability.
This attempt by Okawa was just one phase of his efforts to save Sega as he reportedly sunk $900 million of his own stash into the company to keep it from failing. The Dreamcast is one of the machines I wish that I owned, and probably will someday unless they're all lost in a fire. It would have been great if I could just pickup an Xbox instead, and it definitely would have done something for Sega even if most Xbox owners didn't know what a Dreamcast was.