I dont think the big uber secret is going to be the fact the game is an MMO, seriously Molyneux keeps saying its something which will drive people crazy and that his team didnt want to undertake the task because it would be so difficult. Somehow I cant see that being a MMO, MMOs are no big cheese- there a lot of them out there.
Secondly, you all may want to check this out,
[ Link ]
Its pretty much all of the coverage from various different sites about Fable 2 collected into a link list by Lionhead.