
So you want not just a strategy game and not just a strategy game with a fantasy setting but a 4X, turn-based fantasy strategy game. That answer received more votes than all of the other choices put together. There are some very good turn-based strategy games out there already. They're not 4X per-se, but they are excellent games. A few I recommend include Age of Wonders 2: Shadow Magic and Dominions 2 (Dominions 3 is in development). Heroes of Might & Magic V was also recently released.
As some people are aware, Stardock has been trying to license the rights to Master of Magic. For various reasons that I can't go into, it's not looking like that's going to happen in the time frame we're looking for. And if we did make a 4X fantasy strategy game that didn't use the name Master of Magic, it would not be a clone of MoM. We would proceed with our own design (though we have some ideas that are similar such as randomly generated maps, city building, spell research, etc.).
Another popular choice was surprising -- NON-MMO RPGs. I have to admit that we'd like to do an RPG. A Baldur's Gate / Planetscape Torment style RPG but with a 3D engine. I think the traditional RPG market has been underserved in the last few years. Oblivion and the upcoming sequel to Neverwinter Nights have definitely helped but I think it's a market that has been under served.
Society, which is a long-term development project at Stardock, got some decent support. It continues forward at a steady pace. The IT infrastructure for it is what ultimately will take the longest to do more so than the game itself. And there was a healthy demand for an RTS. I would definitely like to see an RTS version of GalCiv II -- a streamlined UI with streamlined game mechanics. I'd want to see an RTS with tactical battles that are integrated into the main screen. I think next year when Supreme Commander comes out that the RTS world will be in for some real changes in how games of that genre should be made. Total Annihilation remains my favorite game of all time and I think it introduced a lot of concepts that we take for granted today and its spiritual sequel will likely do the same.
Arcade and adventure games didn't get much support. But come on, who here wouldn't love to see a remake of Planetfall or Loom?
Our eventual goal at Stardock is to be able to release a new game each year. We're not quite there yet but we're hiring developers and 3D artists as fast as we can. Go here if you're interested. We would essentially need to build out 3 full game development teams to do that. We've got just about 2 now so we have a ways to go.