I think adding ground units could add another level of strategy in the game, if done correctly.

I have an interesting idea that could work for GC3.

I don't want to control the individual units in battle, or even really strategically place them.  I like that I don't have to do that for the space battles either.  It can be fun, but there are other games for that.  Adding that level of complexity on top of already incredibely complex game would drive people nuts, and for me at least not make the game fun any more.

Now to my idea: There would be a number of different ground units ( not all that many, I think 5 would be enough) and you gain access to these units by researching the appropriate techs.  Then, when you launch a transport you would decide how many or perhaps what ratio of different units to load into it.  Also, when a colony is attacked you would decide the ratio of different units, of the units available to you, (you would do this without knowing the ratios of the attackers). 

The units would work similarly to how the weapons and defenses on ships work now - some are stronger against some units and weaker against others.  This could also give you an opportunity to exploit another civ by loading up with a particular kind of unit if you realize that civ hasn't researched the tech for the unit that is strong against your unit.  The soldiering ability would still work, just by making all your units stronger overall.

That is my idea about how to make the ground combat more interesting without adding a crazy amount of depth.

Ground combat in space 4X games as a natural extension of MoM's tactical unit battles are something that I've been salivating over for a very, very long time.  Glad to see that it's got the dev's interest as well.

For those who don't like it, it's not a big deal.  Even according to MoM strategy, individual tactical battles could be foregone conclusions based on strategic factors.  In fact, once your army is big enough, you tended to automate those battles anyway.

What you get is character.  Instead of making a "troop pod", you make tanks, infantry, and mecha, and those ground invasion troops have specific qualities that make the ensuing combat interesting - a little bit like extra ship battles.

Mecha counter tanks, tanks counter infantry, and infantry counter mecha.  Or some such.

As in MOO, certain kinds of weapons and defense tech would inherently improve your troops, whereas you can also research dedicated troop improvement technologies.

We don't need a unit tree as involved as Civ IV's.  It can be 10 units upgrades in a line scattered through the tech trees, just like now.

Instead of a city-scape, we would have a planet-scape for battles.  Each continent would have a few tiles in it, corresponding to the tiles in the actual planet screen.  Your troops occupy the tiles, and you could have as many fighting troops as you have tiles stationed at the planet.  As you land, you occupy tiles and then fight through the tiles MoM style.

There will be a GC3.  There will not be a GC2 3.0.

GC3 is expected to be a few years down the road-2012 if I remember correctly but I could be off by a year or so in either direction.