All 50 seat RJ's WILL NOT be gone by 2013. That is a false statement.
I have agreed with Boyd on the RJ glut issue for years now. Yes, many 50 seat RJ's are going away. With oil at $135 and going higher every day, many of these 50 seat RJ's are going away. Probably 70% of the 50 seat RJ's we have today will be gone in the next 10 years. But the fact remains that there is still a market for 50 seat RJ's.
RJ's were designed to serve markets that could not handle larger aircraft. Airlines used these jets for many other roles that they were uneconomical in. High frequency flights between large airports was the biggest example of improper use. This is where you will see the biggest reduction of RJ use. Routes such as LAX-PHX, ATL-IAD, IAH-DFW, IAD-(JFK,LGA,EWR), BOS - (JFK,LGA) will lose 50 seat RJ service with oil this high.
Aside from high frequency/high density airport flying, RJ's basically serve smaller communities. I put these smaller airports into two categories. High yield markets and low yield markets. High yield markets are upscale areas, large amount of business travelers, large amount of international travelers, etc... These markets will stay. Smaller markets that don't provide any of the above mentioned will see reductions. The first type of reduction will be in the amount of hubs that serve that small airport. An airline like Delta with nearby hubs in ATL, CVG, and MEM will not fly airplanes from all three of these airports to a small community. These smaller communities will probably go to 1 or 2 hub cities per airline. Many small communities will lose RJ service altogether. Maybe some of them can be supported by 19-30 seat turboprop's, or will get an EAS service. But ultimately, the number of small communities served with air travel will go down because of the price of oil.
But regardless, 50 seat RJ's will not be completely gone in the next 5 years.
Larger aircraft are coming. Major airline scope clauses need to improve. In addition to the jet seating limit (50 at CAL, 70 at UAL/AMR, 76 at DAL/NWA, and 86 at US Air), things like maximum takeoff weight, and maximum number of 70/76 RJ's flown at a regional need to be restricted. I know AMR has a limit on 70 seaters, and DAL/NWA have a limit on 76 seaters. Don't forget to add turboprop restrictions into scope clauses. The last thing we need is a 100 seat efficient turbo prop to show up at a regional. If ever there was a time to improve scope in major airline contracts, it is now. These new aircraft need to be mainline.