Xbox live Rewards just announced via twitter that you will soon be able to receive rewards based on your achievements. Unfortunately they are unable to confirm any details. Hopefully they will actually give us Microsoft points and not just more garbage for avatars.
We’ve hit 50,000 followers, which means it’s time for an announcement! Coming Fall: a new way to earn Rewards based on your Achievements!
— Xbox LIVE Rewards (@XboxLIVErewards) June 19, 2012