As is shown in this new mockup from Stephen: http://people.mozilla.org/~shorlander/mockups-interactive/awesomebar-results/awesomeBar-results-tabOrdering.html

Does that mean we implement the double selection (real/hover)?

I'm not sure I understand the question. Selection is blue, and the only time that both a result and a one-off should be blue is when you key down to a result and alt+up/down to a one-off.

Working on this as part of bug 1295458.

Status update for this bug: this is entirely part of bug 1295458, so when that bug is fixed, this one will be too.

per comment 4

The implementation of the hover/mouseover state is not exactly as in the mock-up from the Description. For instance, I see the following: - in the mock-up on mouse hover the one-off buttons have a clear and bold focus ring around each button (lines going from top to bottom) but with this implementation, the lines of the focus ring are interrupted. - the background of the one-off buttons seems darker in the mock-up but with this implementation, the background of the one-off buttons is lighter (this make the hover/mouseover state much more discrete especially on Mac OS X) Was this intentional? Also, please be aware that there are some hover/mouseover issues when high contrast themes are enabled on Windows. Logged Bug 1358136 to cover this.

Thanks Simona, you're right on both counts. It looks like Stephen's CSS is using an alpha value of 10% for the one-off hover, but I used 6% for some reason. I'll file a new bug for each of those.

I filed bug 1358676 and bug 1358677.

Based on Comments 6 and 8, and considering Bug 1358677 and Bug 1358136 are tracked in Bug 1180944, marking this as Verified Fixed (verified on using Nightly 55 on Windows 10, Ubuntu 16.04 and Mac OS X 10.12)