I just wanted to add that Project Red was able to have steam distribute a DRM free version of Witcher 2 through steam, I don't have a ton of details, (I bought it through GOG.com) but it is possible to do. Perhaps Stardock could investigate this.
Well, Trinity is was without copy protection and without any real DRM... and it was released on Steam too...
Steam is used as distribution platform and you don't need to include Steamwork for it... if Steamwork was added to Rebellion, it was too please the multiplayer communauty... you know, these very little group who are maybe in the hundred, almost nothing when compare the the millions who don't play the game online...
Some guy have orgasm now because they can show their achievment online, when previously, it was only internal to the game...
Well, it is not the subject... in short, the reason of the Stardock move to Steam is not DRM related...