Kinect could have some interesting achievements.And it could take a picture of you when you unlock achievement.
Personally i don't care about them but apparently there are tons of people that care.Various forums are full of posts about "need help with achievement x".Releasing a game today without achievements is "lol,no achievements,shit game,meh",if somebody told me that 10 years ago i would laugh at him.
Unlocking achievements is a game now,"game within a game"...