And maybe someone else will run.
Matt Blunt: 37 on election day 2008, Secretary of state from 2001 to 2005, State Legislator from 1999 to 2001. Currently has a 36% job approval rating after a first year where he kicked a bunch of people off of medicaid, while also endorsing embryonic stem cell research.
Jay Nixon: Attorney General from 1993 to 2009, ran for the Senate in 1988 and 1998. Got squashed by Danforth in 1988 and lost by 9 points to Kit Bond in 1998. Won re-election with 59% in 1996, 60% in 2000, and 60% in 2004.
So basically this is a matchup between the unpopular Boy Wonder, Matt Blunt, and Jay Nixon, who isn't totally loved by Democrats.
Of course, the fun occurs down ballot, where I'm pretty sure someone like Gibbons or Koster could run for Attorney General, and i'm also suspecting that Matt Bartle could try and run for Attorney General.
But yeah, take your pick, Little Blunt or Jay Nixon