Re: I know a secret...
Well, I'll bet on a 6.5 WSM from Win and Rem has the 6.8 SPC, right? So, I'll say if Win does a 2.5" case with the .555" base, we'll have some excellent fodder for the gunmags to spill ink about. A 416 or 458 in this config would win the hearts of qutie a few African dreamers, and give us all something to do with that Mauser action in the closet.
Remington is kind of stuck, case-wise, because they can't reasonably go any bigger, and to go smaller would be in some way to concede the idea that the RUM case is too big. It would be a trick to say the least, to pull off the successful marketing of a smaller case in 308-375 caliber without hurting their RUM sales.
And short actions have pretty much all they need or can take from the 308 case up to the WSM.
Maybe Remington will hype up a rifle built around the SPC, in a light "deer hunter" configuration. Maybe titanium.
A 110g (or whatever it is) at 2800fps from a 22" bbl, in a gun that weighs 6# all-up, for under $1k. That's marketable.