I was curious if/when you'll be adding a full screen Lion option? I use Firefox 7 and would like this added.
This feature is currently under development. You can follow the developer discussion.
Since this isn't done yet, the earliest it could ship is Firefox 10, in January.
FYI: Firefox 10 is out & there is no support for Lion full screen.
UPDATE: Firefox 11 is out & still no support.
Lion Full Screen app support is in the current Firefox Nightly version, so should ship with Firefox 14 at the latest. I can confirm it's a nice feature and works well.