I would say given their very recent track record, you should expect them to release versions that have been tweaked to work on modern hardware. What that means in terms of multiplayer, who knows. But you should expect the single player to work splendidly on new systems. They know DF can't just run via magic. This ain't the old Lucasarts.
They already released stuff like The Dig and Indiana Jones & Fate of Atlantis on Steam, and they didn't use SCUMMVM or DOSBOX. I think this is an attempt to reclaim some of the old reputation they had, rather than a quick money grab.
"LucasArts Planning Many More Retro Remakes, Re-releasing Jedi Knight Next Week"
http://www.shacknews.com/onearticle.x/60413