the concept...
well, nothing unexpected, the new 5th series had to become M some time... right?
i think they got the car totally perfect in the previous model, so it was right about time to switch over to the next design and start perfecting it over the years (bmw is good at stopping at the right moment... mb couldn't do it, when i saw a next version of sl500 i was like yuk, last one was the thing, this looks like a parody)