Given the success of the Sd'd more recent titles, be it in-house or just as publisher, i really would not be surpeised to see GC3 take a different direction, even if slightly.
Both SINS and Demigod have seen huge success with both having MP, and mroe than but the MP is a big feature, if not the whole core of the game.
Even though i am a huge fan and promoter of the Metaverse i could see it making way for what would make a far more profitable MP system, though being TBS could stress that feature.
I can just see Brad and co now looking at and comparing SINS sales and DG sales to GC2 and thinking "damn i want to get those numbers for a game we make...ohh look GC3 is on the horizon.)
Be it the MP route they go down or the RTS route even, i'll be interested but i wont even think about looking for journals for at least 2 more years.
Between now and then, we'll just have to cope playing GalCiv2 and Elemental. I think we'll live.
Throw Demigod into that mix. Though, who is to know what new big title is just around the corner that SD might be publishing.