I have not seen this coming to be honest , all indicators and all leaked news from the brotherhood were in to the opposite direction. I swear if it were announced yesterday , I would thought it as April fool.
The breaking news of the day : The Muslim brotherhood announced its support to the coming 6th April strike 09 next week and it even is calling the people to join it !!
You can check their official press release at Ahmed Abdel Fatah "in Arabic", more updates are coming.

The Source