Someone earlier had mentioned GR desire to make each system fit the setting. While MnM can be used to create just about anything, I bet we will at the very least see a modified version of it, perhaps a standalone, if they use it with DC. I'd be happy with that.
On the other hand, I still think its likely that we will see some kind of independant system. Hopefully one that is, at first glance, better than the late Marvel RPG.
3 out of 4 of my group are really into comics, including me, and one has already expressed a desire to play in Starman's Opal City. Given how that particular series ended and the relative lack of development since then, I think its a great idea. I'd love to see them take the names of some of DCs Z-list characters and try and come up with a cool character to match it. I, of course, am already plotting. As i frequently do for games we will never play. So many games, so little time. Sigh.