Oh, I've played PS:T like 5 times and bought it at least twice physically haha
It's really interesting, I think, that both "single player only" and "multiplayer focused" players are both represented so enthusiastically here. I think that it really says something for the game that completely different aspects have such ardent support.
I'm not sure I said it in the thread here, but I liked a lot of what went on in SC3 also (I know, also a heathen) with a lot of the aliens/voice acting (I like the Orz voices from SC3 more, much more how I remember them when I replay SC2 without voice acting.)
I agree there really isn't anything out there like Supermelee. I'm pumped for it coming back.
I don't know if it's actually true that it's comparatively little work to make good multiplayer - think about how long it took for TF2 to come out - it wasn't the graphics, not really, it was the balancing. It's such a tricky thing.
In terms of Supermelee, I feel like a lot of the house rules could be implemented (and I wouldn't be surprised if this is how stardock is already approaching it) similarly to how you pick an array of options when starting a 4x game (like civ) and then set your house rules that way. I remember having similar house rules at times.
As for more complicated multiplayer scenarios and game modes, I do think that approaching it by robust modding toolset may still be the best approach, considering the amount of work that goes into producing a balanced and enjoyable single player game. They've already talked about being able to create your own ships/races/plots/etc using the toolset, so it seems like you could make a tweaked version of the ships designed specifically for the modes you are talking about - if the toolset is good enough, all that should be required is the amount of enthusiasm demonstrated here, I think.