Here's my ultra-important and informative take on it. Fable 2 was aimed at 'casuals' and the PC casual market exists only on mid to low spec machines. Fable 2 on the PC would require a mid to high machine to run fine. So it went to being a sofa-loafing game on a console that certainly wasn't going to be any other console due to Microsoft backing it.
But Lionhead are anything but casual. Black and White falls flat the moment you have to compete with the horrible cheating AI gods that actually *steal trees from across the map well outside of their influence circle* meaning no matter how good a cultivator you are, the map will be bare in 2 hours. At Bullfrog Molyneux made Syndicate, then Theme Park and my assessment of them is that they are not casual. Neither was Populus. Molyneux has big ideas, he's a hobbyist game developer: he should be catering to hobbyist, dedicated gamers with big ideas. Those of us who wished when we were kids we could run around actual cities the size of cities in games, rather than just maps that were 'representative' of cities and now can. That's the kind of thing Peter Molyneux should have been first to make.
If Fable 3 doesn't change for those most likely to buy it, it will tank. Many wouldn't have bought Fable 2 on PC anyway because of the unforgivable gap after the release on console, so if Fable 3 is coming to the PC Lionhead need to sweeten the deal or make a loss.