Well... just my two cents, but if IC did something NEW, like they did here in Sins, mixing RTS and 4X then we might expect something along the lines of...
RPG/RTS?
It would be cool to have cutscenes of your crew rushing about the ship preparing for battle, or running as a bulkhead blows in!
A sandbox, with battle cutscenes doesnt have to be a campaign, and could keep the game open ended. One of the things i have come to really like about Sins, is no matter how often i play, when i come back its a new game, new setup, new buildup...etc...
Keeps it interesting instead of reaching the end of the campaign and ending there.
Longer game life it seems to me.
Just my opinion,
-Teal