Firefox differs from Chrome in that it will enable Flash for a whole page, rather than per-element. This means you still need an extension for blocking Flash ads on Flash video sites.

Firefox's model is better, I think. Plenty of sites use hidden flash videos for various utility functionality. How are you supposed to click on these hidden videos so that you can enable them?

You can get the equivalent in Chrome by clicking the puzzle piece in the location bar and selecting "Run all plug-ins this time".

And that extension doesn't work if javascript isn't enabled for that page :(