If I remember well, in the past a post edited more than 10 times became automatically community wiki. Nowadays I've seen a post edited 15 times and nothing happened. Should I deduce that the rule was abrogated?
I think it is not nice to leave the users the possibility to edit their posts how many times they want since we all know that some of them are using this only for bumping up their question on the front page in order to draw attention.