Cochran has won 6 consecutive statewide elections since 1978 and the national news media are mistaking that he's been in the Senate since 1973 when he was elected to the Senate back in '78.
http://en.wikipedia.org/wiki/Thad_Cochran
I also give Cochran a 74% chance of winning the runoff based on his deep experience and I've gotta feel that assuming he wins the runoff and general, 2014 is likely his LAST political campaign.
I view Cochran as the favorite. McDaniel has campaigned in a way that makes him vulnerable to a Democrat like Childers, even in MS. Cochran has the advantage of being perceived as more electable in the general election, and the GOP can't punt away sure seats if they're going to take back the Senate. If control of the Senate weren't so up for grabs, McDaniel would have already won, but no one in the GOP wants to be responsible for this year's Sharron Angle.