If they would just have based ECMA4 on Actionscript and stuck with it, we would have had all the things we're still missing in javascript long ago. All this complaining about "proprietary" platforms is just depressing. When people complain about the need for plugin player with flash etc. and how Javascript is so much better since you don't need external players I mentally mark them down as idiots.
The only difference between Flash and Javascript from running perspective is that every browser has included the Javascript runtime in the form of Javascript parser, if Flash were included in the same way (especially now that it's an open format) there would be zero differences between these two, except that you could use an actually sane programming language instead of one that lacks consistency and has all the hallmarks of homebrew script language.