Khatami Pulling Out in Favor of Mousavi?

It's being reported that Mohammad Khatami is going to withdraw from the Iranian Presidential race in favor of Mir-Hossein Mousavi. That would at least reduce the likelihood the reformist wing will split its vote among several candidates (though Mehdi Karrubi may still run); it also means that Mousavi, who doesn't have some of the baggage Khatami has (such as resentment by the student movement of crackdowns during his presidency). One question is whether Mousavi is well enough known to the younger generation of voters (he was Prime Minister back in the 1980s), but he may be a stronger challenger to Ahmadinejad than Khatami would have been.