Egyptian military to govern until elections later this year

It's not obvious why a unity government wasn't possible until elections.
The military could have been a lot more one-sided during the protests but they also weren't neutral either.

Will the military be an honest broker until elections?

The Egyptian military has rejected the demands of pro-democracy protesters for a swift transfer of power to a civilian administration, saying it intends to rule by martial law until elections are held.

The army's announcement, which included the suspending of the constitution, was a further rebuff to some pro-democracy activists after troops were sent to clear demonstrators from Cairo's Tahrir Square, the center of the protests that brought down Hosni Mubarak. "We do not want any protesters to sit in the square after today," said the head of the military police, Mohamed Ibrahim Moustafa Ali. Many agreed to leave but a hardcore refused, saying they would remain until the army took a series of steps toward democratic reform including installing a civilian-led government and abolishing the repressive state of emergency.

The ruling military council said it intends to retain power for six months or longer while elections are scheduled and will rule by decree. It suspended the constitution and said a committee will draw up amendments that will be put to a referendum. It also dissolved the widely discredited parliament, elected in a tainted ballot last year.