I just located this topic and got really excited.
I stopped playing any games from Stardock many years ago after I had a disastrous incident with Stardock/Impulse and lost the ability to play a few games I own. (That and I really didn't like how Impulse worked - but this is a moot point now)
If this is released on Steam I will purchase it immediately. I have transferred my entire gaming collection to Steam and have 437 games there now, I don't think I will buy Games from another platform anymore just because it becomes impossible to keep track of them all. It is worth noting I re-purchased some of your games (Sins, GalCiv 2) when they finally appeared on Steam.
As an additional point - Steam is used by so many people now that whether or not people from *this* community will buy it is really not the question you should be asking. It doesn't matter, most people here will buy the game regardless. (Especially if you offer a boxed separate copy as well)
Much more important is the fact that Steam will give the game an enormous amount of exposure, especially if it sells well, since it will hit the front page on the Steam Store and lead to a lot of impulse purchases. The only sticking point is the price, it's quite a steep fee for games these days.
I'd like to refer to Paradox Interactive for an example of a company who market their games in a very clever manner:
1. Their games can be purchases in non-Steam, seperate boxed AND digital format. (Usually Games Gate)
2. Their games are on Steam. (any recent ones are anyway)
3. They tend to ask a very reasonable price for their games.
Releasing this on Steam is a win-win, and allows you to use their platform for future multiplayer as well - which is a proven, stable platform.