The always reliable IMHO Omar Ashour, from Exeter University, has a short gloomy commentary 'Will Egypt's Muslim Brotherhood return to political violence?' on the BBC:http://www.bbc.co.uk/news/world-africa-28524510

He concludes:
The Brotherhood leadership so far stress that non-violent civil resistance tactics are their means for toppling the military-dominated government.

But organisational fractures under heavy repression, offshoots, disaffected members, and mutiny against the leadership have happened in earlier crises and have happened in a limited way during the current one, the worst in modern Egyptian history.

And in a regional context - where bullets keep proving that they are much more effective than ballots and where eradication is more legitimate than compromise - the prospects of sustaining non-violence become gloomier