Supposedly, S&W and Walther entered into an "agreement" to share technology and Walther is not owned by S&W. The real scoop is anyone's guess, but, if anything, I would tend to believe that Walther is the big dog in the pen.
The europeans mostly think we are crazy for using large caliber pistols, and there is zero market anywhere in the world for a .45 except for the U.S. I have a buddy who is a Canine cop in a very small, quiet German state who sometimes forgets to even carry his pistol on calls...SigP6 9mm. They have rifles back at the station (FALs) but they never shoot them or train with them. They WILL, however, beat and dog bite the ever-loving shit out of you if you resist!
I would say we'll never see the Walther in .45, but I could not believe it when they came out with the .40, so maybe there is some hope.