I am sure we will be seeing far more european styled coaches that will get significantly better MPG than the old V-10 but at a cost. Having traveled Europe in and RV I can say that those coaches are great for sleeping and drive very well but the american RV user is going to have to change their RV habits and not tote/haul as much "stuff" as they do now!
I'd hate to have to "sacrifice house for hood." I love my setup exactly as it is, but 25 feet is the max that I want or need. It fits so nicely into even relatively tight camping spots and I have so much room for all that schtuff!