In a way - and I don't like typing this - this is almost impressive.
Sort of like Algeria '92, but SCAF hasn't completely junked democratic institutions yet. I suspect they and the MB have devised a Pakistani-style plan: military controls foreign/defence policy while MB takes domestic, so long as they don't do anything that would jeopardize Western arms sales.
We won't know until after this weekend, but it might be that SCAF struck a deal with Morsi personally, where Morsi throws the rest of the Muslim Brotherhood under the bus. The MB in Parliament continue to say they're going to resist this (as well they might: they're losing their jobs here), but Morsi has been positive about the move.
Alternately, Shafiq could win and this whole conversation becomes moot.