How about Stardock take Sins of the Solar Empire and make a persistent RTS / MMO game out of it.
How? Well . . .
#1 The player has a level determined by a on-going score. The on-going score increases for either; beating other players in PVP scenarios OR beating PVE scenarios with varying levels of difficulty. Once a PVE scenario has beaten it's score reward is permanently reduced for that particular player. Seasonal PVE event scenarios could be repeated multiple times a day for regular scoring rewards. PVP scenarios are not reduced for repeating the scenarios; but are ranked by "level" range, and have a daily limit until reduced scoring begins to affect the player.
#2 At the beginning of every scenario the player begins with a fleet, and in some scenarios a home system. The size of this fleet is determined by the players "score" but also may be modified by research tree advancements. Like wise the players Home system maybe affected in the same way. A player may modify their fleet and home system in similar fashion as normal game play; WITH ONE IMPORTANT EXCEPTION. When the player logs out, the fleet and home system are saved as a profile. When the player log in, the profile is loaded. Depending on a scenario, the player's home system and fleet "profile" is loaded into the scenario's map as a "instance". Depending on the scenario's defeat trigger; when a players home planet is destroyed the player is removed from the scenario and the instance remains for the remaining players of the scenario, but the defeated players home system is now a separate instance for the defeated player to rebuild. When a scenario's victory trigger is activated, all victorious player's fleets are transported to the scenario's exit location on the persistent map. All "instances" are dropped, and scores are rewarded.
#3 Basically tweak the Cost and/or Time multipliers of Building Ships, Constructs and Research Trees. Building units have a larger scale of time, BUT scaling up cost by a multiplier will scale down build time by a proportioned (not proportionate) multiplier. An example might be; x4 cost might yield /2 build time, while x9 cost might yield /3 build time, and x16 cost might yield /4 build time. How quickly a player can turn profits on the market, during a scenario; may be a important component, in addition to the tech tree.
#4 A persistent Galaxy map where a player can move to a entry points of the persistent map in order to activate a instanced scenario zone. Some instanced scenario's may require player groups (alliances) to be formed prior to starting the instanced scenario. Adding players to the group after the instance has begun causes a failure trigger. A player moving through the persistent galaxy map may encounter PVE random encounters, which may be worth score depending on the encounters relative "level".
These are just some ideas. I would not mind seeing Sins of the Solar Empire having a persistent RTS-MMO version put out to market. It would require more thought and tinkering, but I can already see many of the elements of this game incorporated into such a project.