I guess we won't see any 2-seater in the next DCS serie, because then you have to deal somehow with second pilot-or you have to play with autopilot and rely on him, or you have to find a partner, but then it won't be so popular... And long-range aircraft is also not really probable-the missions will be too long and boring and of course will not attract a lot of people. Don't forget, ED also don't work just for fun-so commercial benefit will be low... Even now they have a small niche of realistic sims-i and you, i suppose, like it, but much more people find it boring and prefer Dead Rising or something like that.
So i think will be something like light-weight short to middle range 1-seated aircraft.