CSE HTML Validator

I was looking at this article http://bit.ly/f714Hq today. It lays out the roadmap for HTML and Silverlight (within MS) seemingly from the decision makers.

It made me think about the different technologies out there. That have been, that are...

HTML, AJAX, Client Side JavaScript, Flash, Silverlight, SMIL, DHTML etc., Air, ASP, ASPX, PHP, Java Applets

Anyone got insights into how they decide which ones to try and which ones endure?

Quite interesting to read on Microsoft on Plug-ins vs HTML5. Specially I enjoyed reading it because it is a topic of concern as i am a silverlight developer