In the real world of software features, managers will take 500+ software updates suggestions from users, sales and engineers. Each of these suggestions are assigned a cost related to how many man hours it would take to implement. Departments are then given a fixed amount to spend on that version.
Stardock could do something similar with Elemental. Now, the major changes and direction of each expansion would be decided by Stardock, but all the little ideas should gathred together and assigned a point value.
The top 500 of these small suggestions should be posted on the website and registered users are given 100 points to distribute. Some suggestions may cost 5-10 points while others might just cost one. The results are tallied and the top 20 are placed in the design queue for the next expansion.
This would really stimulate sales and marketing and get people excited about upcoming expansions.
Once modding goes full force, I would like to see Stardock hold 'design a monster' contest with the winner incorporated into the game. This could also work with castles or other models.