A couple more I wanted to suggest:

6.  Joe Biden – He briefly flirted with a Presidential run in the 80s before someone noticed he had been a bit of a plagiarist.  And he’s from Delaware.  Even if he has the full support of his home state that’s only 3 electoral votes.

7.  Evan Bayh – Indiana Senator who, like Warner, is very popular in a red state.  Photogenic, but is that enough?

8.  John Edwards – Ex-VP candidate and generally charming individual.  Essentially no experience though.

9.  “The Ex’s” – I mean Al Gore and John Kerry.  The major parties generally have a one-strike-you’re-out policy when it comes to candidacies.  However, Gore has been getting mighty feisty in his speeches recently and Kerry…well, Kerry’s got lots of money.  Who knows?

10.  Barack Obama – Ok, ok, I know he’ll have only been in the Senate for 4 years at that point (and only 3 when he’d declare his candidacy) but let me paint the picture for you.  First of all, most observers agree that Obama is smart, savvy, and one helluva speaker.  His DNC speech in 2004 was the best speech this casual observer has ever witnessed live.  However, let’s say the Dems win in 2008 (as I currently think they will).  In 2012 they will of course nominate the incumbent, forcing Obama to wait until 2016 to run.  As we all know, of course, 2016 is the first year yours truly would be eligible for the Presidency, so clearly Obama would have to wait his turn yet again.  In all seriousness, here’s his best bet – run for governor of Illinois in 2010, serve a fine term, and then run for President in 2012 (if the Dems lose in 2008) or 2016.  But will his young-ish power have turned to elderly politicking by then?  Who knows.