It might be better for me to throw this in the iDrive review that I posted a few nights ago, but I noticed something interesting about the steering wheel up/down buttons today when trying to select a song. They are backwards. Up is used to go back, and down is used to go forward. I could swear that my 335i was the other way around, but I guess it is possible that this is just how the M3 is. I haven't seen anyone else mention this before, so I'm banking that this might have to do with the new iDrive.
Thought it was worth a mention...maybe someone can tell me that I am wrong and that it has always been like this.