I think that "dropping troops" is a good idea, but I don't think there should be a pause to switch to another land-based RTS.  There should be an understood ground war, but there is no need to zoom in and see it.  Training the troops could add another economic element to the game as well.

Troops should allow for conquering planets with strong culture, and strong culture should aid the resistance.

I also think dropping infiltrators, similar to the maurader's subversion ability, to slow production, steal, or sabotage would be a fun addition to all races.

We definitely don't want another EaW, the land combat system it has is abysmal, almost an afterthought, the number of units that can be deployed on the ground is so small in comparison to space, definitely not a pretty sight. If it wasn't for mods, EaW would have died a painful death, then there is FoC and the ridiculous Zann Consortium. Don't get me wrong, I like the idea of the Consortium, but they were so poorly implemented as little more than Petroglyph's dream team, we definitely don't want something else like that. Mods are primarily the only reason I still play EaW and FoC at all. Land combat isn't a good idea, maybe the addition of more ways to influence planets themselves, but definitely not land combat as a whole.

The closest thing to ground combat I would accept would be a ship ability that causes damage over time to a planet's surface.  Maybe add a planet upgrade that reduces this damages duration and effect and researches that increase it to a degree.  Beyond that, it'd kind of take away from the games space-focus too much.

-Twilight Storm

Not even a snowball's chance in hell. 

I like land-based RTS, but Sins (this game) is not it. A future land-based RTS based on the Sins lore would be cool though.

This makes a bit of sense when you're trying to retake a planet.

bombing = infrastructure destroyed. bombing vs invasion is dependent on what you want it for. if its a big fiancial or production center that you want intact, or want the people as new "workers" bombing is not a good option. if your want to build your own thing entirely or just want the planet for strip mining, bomb the crap out of it

I don't mind land based stuff but I wouldn't like it in Sins.

Some company is working on a game in which you can seemlessly fly a ship from interplanetary space to the surface of a planet.  Guess what?  Landing takes a couple minutes (unless you want to burn up in reentry).

I would love to see a troop transport ship or the like that would be able to capture structures or planets by the deployment of troops.  Invasion is costly to do, but also lets you keep the infrastructure already on the planet for instance.

As for another game set in the Sins universe that takes place on land?  Would be awesome, but I don't know who would develop it...  There's a big difference in RTS games versus FPS games...  I guess you could have a land-based RTS, but still...  Regardless, I get the vague urge to use microphasing to phase enemy tanks out and let gravity make them fall towards the center of the planet where they un-phase and blow up because of the pauli exclusion principle 

It sounds like a good idea, but one thought I have to put forward is this; how would you track ground assults? I mean, maybe if Sins had a campain they could have specialised missions on key planets, but during a multiplayer it would be difficult to mangae a ground assult and a fleet

Well you can always mod it so the when the ships shoot the planet instead of showing missiles the ships can shoot crates which you can pretend that they are sending troops down to the planet

Actually, a better system, if gound warfare was to be considered, would be something like Star Wars: Rebellion.

You have troops which you load on your capital ships, troop transports, and planets (in Sins, it might make sense to put them on siege frigates). Then, instead of bombing the planet, you try to invade it. If your army is better than the opponents (with some random numbers thrown in), you take over the planet. However, you could install shield generators so that they could not invade, first you have to bomb enough to take out the shield. I would say that planetary defense upgrades should grant a few troops free, but you can always purchase troops and garrison them on the planet.

Simple mechanic. great strategic oppertunities. Makes the siege frigates useful.