I've avoided calling the 800 number yet, because I know that once I start....
For what its worth, a local Bay Area dealer had a Mineral Gray 135is convertible that I drove - and it has been there a couple of months now. The color looks awesome, and I seriously considered it. You should be able to watch the video and see pictures of it here (though it is much nicer in outside lighting):
http://www.stevenscreekbmw.com/new/B...1fc5c4f5c5.htm
Hope that helps your wait!