Comment 9 for bug 239926

Both Nautilus and Epiphany behave this way for their Bookmarks menus. They also respond to ctrl+click, which the awesome bar already supports. I'm not aware of this behavior on other platforms or browsers, however.

The feature fits well with the semantics of using middle-mouse to create new tabs, as well as adding consistency to the interface (wherever a user can ctrl+click, they should be able to middle-click).

There is a general need for better discovery for UI generally (as evinced by frequent user discussions about features found by chance), but this feature does not seem to make that problem better or worse.