I think there are still some Dreamcast games on the horizon, but nowhere near as many as for for the 'living' consoles. As for the MMPORG servers (like Phantasty Star Online) they've basically said they'll keep running the servers as long as people keep playing the game. (ie as long as it's stil profitable, I guess)
Still, Dreamcast seems to have picked up a bit of a hacker following, but that too may well die off once PS2 Linux is widely available. Who knows.