Navigating the Dash search results is not a very good user experience.

I hit the Windows key and type "fr" for example. A number of applications are shown. Intuitively, I hit the TAB key to cycle through them. Nothing happens. I then hit the down arrow to quickly skip to the next row - nothing happens. The only keys that seem to be usable are left/right arrow keys. Either that, or the user must type more letters to narrow down their selection, or use the mouse (not ideal). The user's hands are already on the keys, so it's extra effort to stop and reach for the mouse to click.

My suggestion:

Allow TAB & shift-TAB to move forward/backward through the apps (left/right). Allow up/down arrow keys so the user can skip faster, to further rows down.

Bonus feature:

More flexible memorization of apps based on keystrokes, e.g. using "ff" to associate with "Firefox," or "trs" for "Transmission." Launchpad on the Mac works in this way. It's simply search with wildcards between each letter. Once you use the same association a couple times (trs -> Transmission), it's memorized and that result will come up when the user types "trs."