Richardson is practically running already, and Biden is probably going to get in (but might drop out early).
You left off Edwards.
People were contacting the DNC during the DNC race, including Kerry, Bayh, Warner, etc. talking to the people running about their help during the 2008 primary. Edwards didn't even contact them once. I really don't think he will run again, although I hope he does!
"Sen. John Kerry (D-Mass.) is vetting the leading candidates to be the next Democratic National Committee (DNC) chairman, and asking them to remain neutral in the presidential selection process in 2008. It is the latest indication that Kerry is putting down markers to run again for the party's presidential nomination in 2008.
His outreach to DNC candidates also marks his return to the fray after Iowa Gov. Tom Vilsack, that candidate he was backing for chairman, ruled himself out of contention in November. The DNC contest is exposing the presidential ambitions of a number of Democratic politicians. In addition to Kerry, other potential 2008 presidential candidates have also contacted -- or been contacted by -- the several DNC aspirants, providing an early list of who is sending clear signals within the party that they will run for the Democratic nomination.
Over the past six weeks, Sen. Evan Bayh (Ind.), Sen. Hillary Clinton (N.Y,), New Mexico Gov. Bill Richardson, Virginia Gov. Mark Warner and Kerry have been in touch with former Denver Mayor Wellington Webb and former Michigan Gov. James Blanchard, said Webb and Blanchard -- the two DNC candidates who agreed to speak on the record on this issue. Those are the same names that several other DNC candidates, or their campaigns, have privately said they contacted."
http://www.dailykos.com/story/2005/1/12/133719/480As for Richardson, I read the things about his comments regarding his run, but I just have a gut feeling that he won't.