It's always going to be something. First it was for them to solve some software glitches in the 07, then the diesel model to be released in 08, then the M Sport in 09. After the new Idrive is out in '10 they will be doing a mid-model life cycle "touch up" which will change the options and look some what in '11. Then will you want to wait for that? By then you're thinking there's only 2 years left until a whole new redesign in 2013 for the 2014 model.
You'll never get there. Just pull the trigger, be happy with what you have and trade in or buy another one when you really want something. Otherwise, you'll never enjoy the X.