TheWitcher: Enhanced Edition Director's Cut is now available for OSX via Steam for $9.99, CD Projekt has just announced. The port requires OSX 10.6.8 or newer, an Intel Core 2 Duo (or better) and roughly 11 gigs of free space. Since it's a SteamPlay title, users who have purchased TheWitcher: Enhanced Edition Director's Cut from Steam on PC will automatically receive the OSX version, and vice versa.
CD Projekt also announced that every copy of The Witcher 2: Enhanced Edition includes a complimentary, DRM-free backup copy at GOG.com, regardless of where the game is actually purchased. Said backups also include any extras that may have been included with whatever version of Witcher 2: Enhanced Edition you purchased, such as art books and soundtracks.