For the time being it's only sure Fable 2 will be released for the Xbox 360. That's the official Lionhead line. Molyneux justified it with:
I'd rather get one single format absolutely nailed, and then think about other formats.
Shame for all the PC users, but at least they'll focus on one game only, so it'll be really polished.
One single format absolutely nailed
It is of course very important for Microsoft Game Studios to get some exclusive AAA titles out for the 360, especially around the time when the PS3 starts dropping in price; they took a hammering with last generation's Xbox and really need to do well in this generation. But they also want to push Windows, especially Vista, onto people, so they need some 'killer games' there too. If Fable 2 sells well they will definitely want it for Windows, and they can just throw some money at it until it's ported - that's not such a big problem. Since the success of the Xbox 360 is more urgent to them (there's no real competition for gaming on computers, but Sony's PS3 and the Wii threaten their console), they'll prioritise it to the 360.
More interestingly, can Fable 2 as a game even be fully ported to a PC? Fable TLC showed that the controls and everything else that was in Fable can be done on a PC, but then Fable 2 will have some new things. Molyneux just keeps hinting about co-op play over Xbox Live.
As a designer, I'm going to rely on that friends list. It's changed the way I think about games. I'm no longer just thinking about you, I'm thinking about you and your friends. That makes a big, big, big difference in the way I approach designing a game.
Xbox Live for Windows
(Word of warning, he might not have been talking about Fable 2 - it could be totally single-player.) Until last week, Windows didn't have access to Xbox Live, but then at the GDC they announced it: the Xbox Live system will be extended to Windows Vista. You can access your account through Windows or the Xbox, and you only need the one account - but you do need to pay for that, same as before. Best of all, you can play Live games against anyone, whether they're using an Xbox or a PC. The first game that is going to ship with Live integrated is Halo 2 for PC, but from now on any and all games for Vista could do. This means that anything Fable 2 does on the 360 it can now do on a Vista PC ... so there's nothing in the way of Fable 2 coming out for the PC.
Of course, that doesn't change the fact that Fable 2 is going to be Xbox 360 exclusive for now; Molyneux is still going to concentrate on that. But it does mean that maybe 6 - 12 months after Fable 2 comes out we could see a PC release.
Quotes from an interview on IGN; the Live story is on the Inquirer.
By the way, < * blockquote>and < * /blockquote> are used instead of [quote]. More details on the forum: 
... People prepared to kill if he doesn't release it on PC... talk about your fanatics 
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