I would vote Al Gore for sure in 2008, if he does not run I would vote for one of these guys.
2.) Wesley Clark (would make a great VP if Gore gets in)
3.) Mark Warner (He was the #1 Governor in 2005)
4.) Senator Bill Nelson of Florida (I know he won't run and don't plan too but for some reason I think he would make a great VP.)
Gore was and still is a long shot. While I can't say he'd win the 2008 race (he did get the popular vote though) he would easily win the Dem primary. It's his for the taken, all he has to do is beat Hilary, which won't be hard if he gets in the race before the spring. All kinds of Dem sites have Gore way ahead of everybody else, so Gore does have support if he jumps in. As of mid-2006, Gore has seen a dramatic increase of support amongst the grassroot Democrat constituency, who have stated a high level of support for a possible Gore candidacy and a surprisingly high number of respondents (68%), preferred Gore as the 2008 Democratic nominee in an AlterNet poll. Plus Gore is always droping hints here and there unlike in 2002. His movie also has help him out in many ways, maybe now he could run on the environment and win this time. It's him or Hilary, no one else can get that much support and money from dems. Plus Al didn't vote for the war in Iraq and he's a southern (last guy to win from the north-new england was JFK).