There’s so much content on http://www.microsoftpdc.com and I’m trying to watch at least once a day. So my PDC Session of the Day is this Building a Graphics-Intensive Application in Silverlight by Seema Ramchandani
She highlights quite a number of things to bear in mind when you’re doing lots of animations, image & video rendering in your application. She also talks about a tool called XPerf which allows to “dissect” your CPU processes in order to analyze the performance of your applications. You can read more about this tool here