However, Facebook's long-press function makes sense inside an app. It's less a webapp there, and more a desktop app--even though it's interfacing with the Internet, it's presented standalone, not as a place to go within another program. You don't expect to see the browser's long-press menu in the Facebook app, because there is no browser.

As for desktop, if they're intelligent at all, they'll use a different method there. Perhaps all the new variations will be displayed side by side. Perhaps instead of only trigfering on a "long-click", it'll expand on a normal click.

Really though? What do you do in the context menu within a browser (assuming you are not a developer looking for view source/inspect element type things?) If that was not my day job I would have absolutely no use for the browser's context menu.

JIRA uses right click, and I hate those fuckers. But that's a rant about JIRA...