As has always happened, Standard and Open Source technologies have always been at the top of all the other technologies. HTML5 is extremely powerful and sooner or later everyone is going to provide support to it. Earlier Microsoft went on with its jargon of Silverlight and did not provide complete support for HTML5 in its browser till IE9. Recently they have announced and released a developer preview of IE10. They are boasting that IE10 provides great support to HTML5 and CSS3 Gradient and CSS3 Flexible Box Layout.
Probably Microsoft initially wanted Silverlight to go like Adobe's Flash and become prominent for internet users, thats the reason they did not provide support to HTML5. But besides providing support to HTML5 in IE10, they have been de-emphasizing Silverlight. At MIX11, Dean Hachamovitch, corporate vice president of Internet Explorer, did not even mention Silverlight even in the keynote speech, according to CNET NEWS.
All this brings us to a conclusion that Microsoft may sooner or later slowly fade out Silverlight development, eventually kill it and adopt HTML5 completely in future.
Lets see how do the web standards direct the growth World Wide Web.
UPDATE: In a recent blog post on Zdnet, I got to read something, that I was hoping to know from Microsoft. Refer the image below.