What that tells us is BMW will learn some kind of lesson from this. Being that as the F10 fly's off lots, the M5 seems to collect dust.
I think it'll be the F10 is so good of a luxury car from the start, the M5 version just doesn't do enough to warrant the "M" tag, due to it now being considered "held back" by what inherently makes the F10 such an incredible Luxury Saloon. The F10 can be specc'd so well as a non-M that it dangers rendering the M5 practically irrelevant. At one time, getting an M5 wasn't just about better paper specs, it was about a more racey and raw driving experience. Not to mention, the 550i being Turbocharged, you can squeeze out "real world" power performance of an M5, or maybe close to it (or maybe more than it), for a lot less money.
Also, the M Sport Package looks so good, that the M5 styling doesn't stand out from it enough so, I think.
People have to keep in mind, the chassis on the F10 is the same chassis under the Rolls Royce Ghost, the latter being just modified and a larger extension of it (i.e F01 chassis which houses the Ghost is an extended version of the F10 chassis). The F10 is such a BRILLIANT luxury car because the inherent chassis isn't a built up 3, it's a built down 7, and actually a built down Ghost. BMW had to over-engineer this chassis to be inherently capable under a $300+K Super-Luxury-Wafter. Some hate that, some love it. The F10's chassis has an incredibly high torsional rigidity figure due to that, to where the M5 didn't need any additional stiffening up from the basic structure, from what I hear.
.... With that, comes a ton of weight, and isolation. IMO it makes the car over-engineered in this segment, but some find it a huge downside as it's now "too much" in that area. What I can argue makes the 535i a much better car for the common consumer (all that said above), may turn off lots of M5 buyers.
'13 F10 BMW 535i Sport
: Jet Black/Black-Anthracite : Premium & Technology Packages/Sport Auto Trans/Camera/Park Distance Control/Heated Seats/Tinted Windows/Blacked Out Markers/Performance Spoiler.
Ex M-B's: '11/'10/'06 E350's w/ AMG Sport Package, '02 S500 w/ Every Option.