New polls have Missouri weakening from being a "Weak McCain" state to being a "Leaning McCain" state... meaning McCain is ahead by less than 5% based on the last five polls in the state. This puts the state in play as a potential swing state and improves Obama's "best case" scenario.
McCain Best Case - McCain 313, Obama 225
Obama Best Case - Obama 344, McCain 194
And if everybody gets their leans (and Obama gets DC) - Obama 277, McCain 261