Adobe is finally facing the truth

Despite the security issues, will HTML5 or whatever it used to replace it going to be a suitable alternative? What's to say its replacement won't have the same security issues?

Yeah, but it will probably have an AAMEE installer or .app.
Just trying to keep the expectations in line :)

HTML5 has been around in one form or another for quite some time now.
Going forward it is the underlying system your browser will use for pretty much all webpages regardless of whether they have flash like content or not and we are going to be using it whether we like it or not, having it deal with the flash type content is simply a small extension of what it is already handling and makes a huge amount of sense given the prevailence of this type of content these days (mostly annoying adverts of course).
The interpretation is done directly by the browser there will never be an installer of any type for it, updating it simply means updating the browser.

Now we just have to wait for Oracle to tell us to stop using Java. :)