You'll probably get a Fable II expansion out of Lionhead. The only time they've ever released two full games even close to within a year was Fable to Black & White 2, which still took ~15 months. Given the lengthier dev cycles this gen, you probably won't see another game from them until mid-2010 at the earliest.
This is the rite analisis.
It's unfortunately a mith that MS announces games the same year they are released (xcept for low budget casual titles like Viva Pinata and Scene it).
I don't think we'll get any BIG unknown game announced that will make it out in 2009.
But I hope Rare will anounce a great game and Lionhead something interesting, innovative like Dimitri or BC.
(perhaps renamed since both those names kinda suck)