The market for the 50 pax jet aircraft is coming to a close if fuel cost stay high. Boyd group recently stated "don't get between a 50 pax regional jet and the desert as you will be run down". It is just not practical or feasible to operate this type of equipment in todays enviroment.....
So where does that leave things. I think you will see growth in the larger RJ type equipment as well as the 100-120 seat aircraft. These types of equipment have much lower CPSM. The limiting factor in numbers will be the scope langauge for each carrier and who will actually fly them.