I'd be interested to know why Smith and Wesson cut ties with Walther America. Do any forum members know if Walther America will still offer US customers a full lifetime service warranty?
From what everyone can gather, it seems to be the other way around.
Walther was the one that sought to cut ties with S&W, largely due to S&W's abysmal marketing efforts with regards to the P99, PPS, and PPQ pistols over the years (which of course happen to compete with S&W products). The P99AS, for example, is probably the best DA/SA pistol on the market today, yet almost no one in America seems to know about them.
As far as the lifetime warranty question goes, I don't think that question has been answered yet. However, with most of Walther America's competitors in the US market offering lifetime warranties, I would be highly surprised if they didn't.