Microsoft brings Silverlight video to the iPhone, without a plugin
It's not as if Microsoft brokered some secret deal with Apple that Adobe couldn't. Instead, they made their own software stream Quicktime-compatible video to the iPhone using the HTML5 video tag. That means you don't need a plugin to view Silverlight video, you can just watch the same H.264 stream that sites like YouTube use on the iPhone. It also doesn't mean all Silverlight content providers will automatically stream H.264, but at least they have the option. Nice one, Microsoft!