Sure...
To port it over to the PC, we need coders. That means nothing for the artists and scripters (like me) to do. So, while the coders ported, we all put in new content. This is new stuff, not old stuff that didn't make it in the xbox version (The dragon is a completely new dragon for example).
MS decides what versions appear on what platforms, so that isn't under our control, and anyway the Xbox got Fable before the PC, so i guess they are just redressing the balance a bit?
Mike.........