The buzz will surround Vice President Biden and Secretary Clinton. I'm guessing that others like Senator Warner may run...but who knows. The Democrats nominate people out of hats. In 1976 it was the random Governor of Georgia, then in 1988 it was the random Governor of Massachusetts, then in 1992 it was the random Governor of Arkansas. In 2004, it was just a random U.S. Senator and in 2008, it was a one-term Senator from a non-swing state.
Compared to Republicans:
68: random failed candidate from eight years ago
76: random congressman who had recently randomly became president after randomly being appointed VP
80: random actor / random governor
88: VP of random actor
96: random senator
00: random governor / random son of aforementioned vp of random actor
08: random senator / random failed candidate from eight years before
in other news, the word random starts sounding really weird after you say it in your head over and over like that.