One suggested a little while back that the law of diminishing returns would start to batter the cruise industry. And one was damned well correct.
I seem to recall being told that the current (2010 ish) break even point was 93% occupancy- ie a fully loaded ship at full prices made 7%... now we're seeing 10-20-30% reductions in fares and it isn't unusual to see X% empty cabins.
This isn't quite so bad when you have smaller ships- but the basic running costs of these mega ships is so high and they have finance obligations for maybe 15+ years on them that you could quite easily see another "wave" of cruise company bankruptcies.
The average top company executive isn't too smart and STILL hasn't woken to diminishing returns.... fools.