To put it simply, I don't know. I do, however, know a little about business.
To me any "increase" would be in a fuel surcharge which may be justifiable.
As for NCL, is it in financial trouble again? I do not know but they appear to me at least, to have a bit more than their share of equipment problems but I may be wrong.
With the economy just now in it's earliest stages of recovery (which may well be endangered by events in Japan), the average American I don't see as yet noticing much of a positive difference, if any. That is why I can't imagine raising prices at this stage in the game unless bookings are way up (only you guys who are in the business would know that as I wouldn't even know how to research something of such a nature). Of course such info could also be considered proprietary, too. But to me, an increase at this time just doesn't jive.
I'm not saying though that lines don't need to increase fares but if they do, they definitely need to make some positive changes. On many lines (RCI) being one, that were noted for their food quality and extensive menus have tanked (in my opinion) along with quality in various areas of other lines. If they were to nominally raise their fares and re-establish their former standards and advertise such, I personally think they would be much better off.
Just my opinion.