"Only on Xbox 360 & Windows," states the box art which has since been removed from the press resource site Microsoft released it through. Earlier placeholder box art said simply "Only on Xbox 360," indicating that either publisher Microsoft has accidentally revealed a PC edition too early or the newer box art was incorrect.
Fable II was said to be "available exclusively on Xbox 360" when it was announced in August, 2009, though the term "exclusive" is often used to refer to a game that only hits one of the consoles, even if it also is released on PC. Splinter Cell: Conviction, for example, was billed as an Xbox 360 exclusive despite also coming in PC form.
The first Fable was originally available only on Xbox but later came to both PC and Mac as the expanded Fable: The Lost Chapters. Fable 2, however, was only released for Xbox 360. Fable 3 is scheduled for release, on Xbox 360 at least, this holiday season.