Allow me to chime in with a few points here and there.
C-2B (by Northrop Grumman): I'm not entirely sure that the company even has the right tools to be able to build it. I'm sure there are a lot of old C-2A tools in some shed somewhere, but we're currently having issues with the C-2A that are difficult to solve because of the era in which it was designed. A lot of the engineers now scratch their heads when they see something that just "doesn't make sense" and yet has worked for 4 decades now. Making a C-2B would be a new aircraft moreso than simply a follow-on to the original or reprocured ones. As Hoover(COD)pilot mentioned, the current platform just isn't very capable. We have 1 main mission, and at best a couple side-missions (paradrops for one). We need an aircraft that can deliver cargo to the ship, carry SEALs many miles into bad-guy territory, and of course give/take fuel. It's pretty much been the trend of the military... do more with less. Unfortunately we're quite limited with the "more" part right now.
Why the V-22 will not work: There are design and operational limitations to the aircraft that just don't allow it to fit in the traditional COD role. Kiss fixed-wing ops at the ship goodbye. Instead, imagine doing "helo breaks" that last over an hour (for the offload and loading of cargo). It would be like when the -53s come aboard during the wee hours. Second, without pressurization we'd be limited on how far we could travel with pax, at least with one bag of gas. The ceiling automatically becomes 10,000' unless you figure out a way to get the passengers to all have oxygen (comfortably). Third, the internal volume is smaller. It is very rare that a C-2 reaches its weight limit compared to reaching the max volume on the inside of the airframe. Simply loading and unloading while aboard the ship would mean less goods coming to and fro per mission. As I mentioned before, the V-22 just can't fulfil the C-2 role as we know it.
Why the V-22 will work: The biggest challenge is to overcome the mentality of "that's how we do business." The V-22 is more capable, but with different capabilities. The flying into bad-guy territory with SEALs can be covered by this airframe. Being able to take fuel is covered, which means 10,000' really doesn't limit range as long as you have a tanker. The challenge now is to figure out how you're going to move cargo on and off the ship. Although it won't work for fixed-wing ops, the V-22 can land on other platforms (small boys, oil rigs) and transfer cargo that way. Helos can then take the smaller cargo back and forth as needed. If big items need to come to the ship, then they would come just like they do with helos now... VERTREP. Even though the internal cubic space is less, the weight allowance is greater. And the V-22 is not confined to carry stuff on the inside. It can actually carry more items than a C-2 if you were to simply take it underneath.
Challenges ahead: Again, the biggest idea to overcome is the "inside the box" for what the purpose of the aircraft is. This means changes to how dets are organized, the missions that are given (cargo vs spec ops vs ???), and who actually owns the asset (airwing vs admiral vs combatant commander vs ???). Without a foreseeable future for the C-2 follow on, it really looks like the V-22 will win by default.
