OK, new here (evident by my post count); I am in the process of negotiating a price for a 550ix and spied this thread. I never would have ordered the HUD but when I saw the images on this thread (and when I sat in a 5GT, which apparently already has the black panel display, even without the HUD) I decided to tick the option, contingent on the display being correct.
My CA just forwarded to me a message he received from BMW on this: they say that for SOP 3/11 or later a color HUD is included but warned that the images appearing on "blogs" of the European dash are not accurate. They are going to be preparing a bulletin/brochure to show what it actually looks like, but that the speed limit detection will definitely NOT be included in the US. The message really wasn't clear if the blackout will be in the US cars so I asked my CA to try again to confirm or deny. If the blackout and gradual lighting up won't be included then I don't need the HUD.
In case anyone wants another source of information, I'll post when I hear back.
Thanks again to the posters who brought this info to light (
).