Army is leaving Conference USA of it's own volition. I doubt that they would join a TOUGHER conference.
Navy has indicated repeatedly that they aren't seeking conference membership at this time.
Both teams are seeking relative idependence to play a weaker schedule. Reason: they're training officers, not NFL players. They wan't a reasonable level of competition.
Very good take on the Army/Navy issue. Basically when everything shakes out, there will be two independents in 1-A - Army and Navy. They can write their own tickets and do what is in their best interest. They know that they won't be able to compete on the BCS level because of tougher academics and the military committment, so they are content with a competative schedule, natural and historic rivalries, the Army-Navy game and the occaisional bonus bowl game.
There will always be plenty of schools that want to schedule Army and Navy just because they are Army and Navy.