Microsoft has this “Silverlight” thingie which is more or less but mainly more a clone of Flash. A fair number of pundits hyperbloviated over it, which reverse-impressed me. Somebody is going to land a punch on Flash eventually, but it’s not likely to be Microsoft.
This was the adoption curve for XMLHTTPRequest, which started out as an proprietary Internet Explorer feature and ended up being implemented by every browser.
The key thing is that Silverlight-specific abilities have to be optional upgrades to the user experience, so that the system has graceful degradation in the absence of Silverlight.