I'm very annoyed about this whole thing. 90% of the people talking about this technologies (HTML5 and Flash) don't know anything about them and haven't got the knowledge to evaluate them objectively.
When I read things like "Not quite that. Flash was great years ago but after Adobe bought Macromedia, Flash slowly became pretty bad and even now its annoying." I don't know whether to start laughing or crying. Since Adobe bought Macromedia the Flash Player virtual machine has risen up his performance a LOT.
It's like saying that a Ford T was a better car than a Ford Mustang.