It seems there are enought rifle manufacturers selling them chambered for WSM that it safe to say they will be around for awhile. It all comes down to whether or not they measure up to other rounds for accuracy and other performance measures. You may not have the variety of loads that you'll see from more "standard" calibers, like .30-06 or .300 WM, but I think they will continue to remain available, if that's what you're worried about.