I would say they are already working on a F10 M5 systems, they got a system on the pace car.
http://www.bimmerpost.com/tag/f10-m5-akrapovic/
And since the M5 and the 550i share the same exhaust setup, except that the M5 has an 80mm tubing versus the 550 that has 70mm tubing.
check out realoem
chances are they will have both.
At least that what id do, lol