So I was thinking, in GC2, ultimately, while there is a variance in strategy to how one can do this, it's ultimately all about targetting the planets.  Even using Terror Stars, while certainly a unique way to do so, is still about taking out your enemy's planets.  The existence of shipyards presents the potential to make galactic conquest no longer be this simple.  Currently, as I understand it, planets still supply the shipyards, and the ability to have more than one planet supply a shipyard does mean you can't just take the planet next to it and hope it goes derelict.  

But what if starbases could do this?  Or if there were high-tech shipyards that could supply THEMSELVES?  Of course, they'd provide no tax revenue and whatnot, but being able to build ships independent of the planets would allow a LOT more complexity and divergent strategies.  Sure, a civilization with no planets, but a lot of shipyards would run dry of resources, but it could still build ships for a while if accumulated a lot of wealth.  If it also has wealthy allies, it can be supplied by them, meaning they are anything but defeated.

Just thought I'd throw this suggestion out there.