Set up landing page that shows themes as well as appearance (ui tweaks) extensions.
I implemented this (as we didn't have a special themes page before, the code here is also completely new), in SVN r10154. Please reopen or spin off bugs if you notice any problems.
Reopening; https://remora-reskin.stage.mozilla.com/en-US/firefox/browse/type:2 is missing the bottom two add-ons that are present in the mockup http://mozilla.focalcurve.com/categorylanding-themes.html
No, actually it's missing the top two add-ons, but the reason is that these are the recommended add-ons for this specific category. Since we don't have any at the moment, none are displayed (but they would be if there were any). Sorry that this keeps you from QAing that part :(
OK; verified with that caveat.