I was hoping that in Suvivor that the last player standing would have a choice to either make a run for an escape vehicle of some kind or continue to blast xenos if he/she chose to.
Left 4 Dead had a similar concept at the end of each final mission...since A:CM is already ripping that game off to no end, GBX should at least make "Survivor mode" a game that you can actually survive if you last long enough.