I'm a massive fan of Homeworld and play it regularly. In fact, I've never found a space-based RTS game that compares with it. I've been looking around recently with the intention of finding a new game that can expand on the fun I had in Homeworld. Also, with my next tabletop campaign being a Traveller game, I'm looking for something in that vein.
I've recently come across Sins of a Solar Empire and this looks like the sort of thing I'm looking for.
An RTS with world-building and a diplomatic/trading angle? Perfect. I was seriously considering EVE Online but I don't want to get involved with another MMORPG - I quit World of Warcraft for a reason.
I think I'll seriously check it out. Looks like my kind of thing when it comes to galaxy-spanning science fiction.