There may not be a coup, but I'm sure a mutiny may be damn near afoot and it may start if Olmert refuses to resign. I wouldn't past the possibility of events that Olmert is being handed resignation papers or "commitment". He is dangerous.
I'm sure many, many Israelis are angry with Olmert about now. Here's an article that talks about how the IDF feels. They were denied victory and aren't happy about it one bit.
Analysis: IDF fumes over denied victory
http://www.jpost.com/servlet/Satellite?cid=1154525850003&pagename=JPost%2FJPArticle%2FShowFull