The wheels are turning, slowly but surely. A BECTU member has recently taken their "employers" to court for flouting NMW guidelines and won.
Equity are starting to make the right noises too. See
http://www.manifestofortheatre.co.uk/ and look at the ideas that have come from talking to members.
Talking about these issues, whatever you think of them is the only way we're going to get progress for everyone.