When / if do you think HTML5 (and beyond) will have parity with Flash?

I know that there are a lot of things you can do in HTML5 that basically obsolete Flash, however there's a huge cache of flash sites for games, etc. that may never be updated. Do you ever see a day when 1) HTML5 (and whatever comes after) completely takes over for Flash and 2) when we can render legacy Flash content in pure HTML5/js?