If you noticed in the details to Fable 2's Collector's Edition, there was an "Otherworldly Bonus" for in-game content. Packaged with the announcement were screenshots, including one conspicuously labeled "Fable2_MasterChief.jpg." Yep, that's not just a coincidence, you're looking at a faux-medieval variant of the Halo superstar. (Halo 3 ending spoiler alert) I guess we know what universe he crash-landed in.
And here we thought Minstrel Chief was the only Halo reference we'd find. Fable 2 is coming October 21 for US and October 24 for Europe.