Nice presentation. I think the Q/A part at the end is quite telling. My take from this is that if you've got some development to do for a real customer now, do it in Silverlight. If you can't do it in Silverlight, maybe only then use HTML5. Even so, since HTML5 is not supported by most browsers, it seems there will be a huge testing effort, together with the usual browser hack code to support older browsers. In the end, why not just use Silverlight? I'm still an HTML5 skeptic