Hi,
B9 is due 2015 I believe, just Google it, there are some artist impressions and also some images (although the car is under a cover and no doubt they've added a body kit to disguise it like they do).
In terms of changes, not my findings but again something I pinched from a Google search:
B8 has Audi MMI 3G, B8.5 has Audi MMI 3G+ (connected Nav)
B8 offers only Hands-free calling via Bluetooth from the factory, B8.5 has both Hands-free calling and streaming audio via factory Bluetooth.
B8.5 has a newer, lighter crown gear center differential.
B8 has hydraulic steering, B8.5 has electromagnetic steering.
B8.5 has an updated front end, including new headlights, new grille, new fog lights, new bumer, new hood, and new fenders. Note: B8 and B8.5 front end parts are not interchangeable without a complete front-end swap.
B8.5 has slight redesigns of various interior pieces including but not limited to plastic dash surround, climatronic