Wow, I can't believe I opened this thread back in 2011. I'm surprised Astro has the funds to afford a ula rocket, but maybe it's ridesharing in some way. Regardless, SpX has lost a potentially high visibility customer, since this is also their Lunar Xprize mission (though..., maybe not, since Google nor the Xprize got any mention in the PR...huh?)
With Chris's permission, an update on this mission. Its now launching on ULA (I assume Atlas) ...