If you haven't seen Justin's Smith's presentation on the CLR Garbage Collector, schedule an hour to watch.
In the first few moments of the presentation, Justin hits it on the head. People see the GC as "an old topic", not nearly as flashy and sexy as Silverlight or LINQ, yet so many people come away from his talks on fundamentals having learned new concepts or approaches.
Justin is one of the best technical presenters I have ever seen. If you don't watch this for the content, at least watch it for his style.