Hi Mark,
Technology should be replaced by better technology. To give you some background: I've written games for all kinds of platforms: PocketPC, Windows Mobile, (Desktop) Windows, Linux, OS X, Flash (AS3), HipTop, J2ME devices and some smaller proprietary devices.
Some of those platforms offer write once, run everywhere. On other platforms every device has it's own quirks and you have to test on every device and implement workarounds.
You might not like Flash, but it is great at running on every platform/browser with the same code base. If you test it on one platform, it runs on all others. (Adobe is also very good at keeping it backwards compatible)
Now, I ask you, what's the alternative for Flash? Does HTML5 offer write once, runs the same on every platform/browser(version!)? No it doesn't, and it never will. Even simple HTML pages are full of browser checking hacks.
Now, if you can offer a programming platform where the games I develop on, run exactly the same on every browser, on every platform, I have no problem killing Flash. But let's be honest here, only plugins can guarantee such a thing.
As to Alex Stamos, the top games on Facebook are all Flash. You know why? Because developers don't have to worry whether or not those games will run inside the users browser. Because once Flash is installed, they will run without issues. HTML5? No such guarantee.
So before you declare EOL, please have a proper alternative, where I don't have to pull my hair and cry all night because browser X on platform Y version Z seems to break the end boss of level 5 in my game because its implementation slightly differs from all the rest.