ZDNet got a chance to speak with Bob Muglia, the Microsoft President overseeing Redmond's server and tools business, and he was pretty clear about it: Silverlight is Windows Phone's development platform, while anything cross-platform on the web will be all HTML5, all the time.
But when it comes to touting Silverlight as Microsoft's vehicle for delivering a cross-platform runtime, "our strategy has shifted," Muglia told me.
Silverlight will continue to be a cross-platform solution, working on a variety of operating system/browser platforms, going forward, he said. "But HTML is the only true cross platform solution for everything, including (Apple's) iOS platform," Muglia said.
Good news for HTML5, I suppose, and for the web as a whole, of course. Silverlight made no sense anyway, since it's pretty much Windows-only; Moonlight barely works, and the Mac version didn't really go down well either.