I just got my F10 last Friday and it was a July build (first week) and has the USB option. The dealer insisted that I needed the Y cable and made me pay for it €65 additionally. So I was a bit annoyed by it as he refused to throw it in when I was paying him via bank draft, so I was interested in this. I just went out to the car and used a standard apply cable USB only and the it didn't really work. I got playback on one song but the menus were screwed up.
I then used the same iPOD classic with the Y cable and checked all the options for the cover art and could not get it to appear on the idrive screen. No option to display it or other indication it could be done.
So the functionality does look to be Septerber Build only.