What has recently changed is
2012-10-16: The number of reviews required to accept/reject suggested edits has been increased to two Network wide (versus 1 before) and three on Stack Overflow. (versus 2 before) Moderators can still cast final vote like before2012-10-16: The number of reviews required to accept/reject suggested edits has been increased to two Network wide (versus 1 before) and three on Stack Overflow. (versus 2 before) Moderators can still cast final vote like before
As I understand it, in particular the edit reviews on SO were appalling with even blatant spam getting through so the problem has been 'fixed' network wide.