I don't see how HTML5 makes authoring tools (commercial or not) redundant. Do you expect people that are relying on visual authoring software to migrate to writing HTML5/JS/CSS in a text editor "just because"?
They could adjust them to output HTML5 with Flash fallback, and that would be a Good Thing. But it seems odd to keep on going with a poorly integrated[1] plugin which duplicates the work done in open HTML+JS runtimes available everywhere from desktops to smartphones[2].
1) eg Flash 'cookies' which don't get wiped when you delete your cookies in the browser.
2) And 'superphones', of course. :-)