I consider the one which had no revenue last quarter besides registration fees to be dieing. (Wasn't asicminer)
The one which is a few months away from releasing an actual product may or may not do well but at least they have a source of revenue other than gamblers and registration fees.
Take a look at these nice graphs
http://www.btcalpha.com/mpex/stocks/s-mpoe/Those graphs show that registration fees aren't the primary source of cash flow, its the options market making activities.
Gambling is also very profitable industry, and BitBet seems to be holding its own; pulling in some high volume wagers over its history. The question remains whether that security and the options market making is enough to keep MPEx profitable in the long-run.
MPEx may be overvalued, but I don't see it as a scam by any means. Everything is very transparent, as well.