Yep - HTML5 = Magic. Won't need no CPU or memory. It will just appear instantly. And every one will just continue to watch HTML5 videos - nothing more than they do with Flash. And even if they do more HTML5 will make it happen totally smoothly - I await the day when HTML5 will make it possible to finally solve world hunger. HTML5 isn't your random tech.
The big problem is that Flash is a single implementation from a single company. It doesn't need to compete with itself to improve as long as some baseline manages to keep stuff like Silverlight from taking share away from Flash. It isn't open.
HTML5 at least says "Here's the spec, implement it how you see fit." You can have Google, Apple, Mozilla, Microsoft and so on all compete against each other to have the best browser that supports HTML5. This means fights for less memory, CPU, and so on, as they try to streamline the experience more.
It won't solve all the content problems that Flash solves, but it does address some of the big ones (video and animated/active content, not so much custom animations and games though).