When using input devices without gesture capabilities, with Lion I would use either the cursor keys to move between panes, and sometimes even map extra buttons on the mouse to Left and Right buttons so that I could navigate Launchpad without keystrokes.
In Mountain Lion, this no longer works as you have to click and drag to move between panes and the cursor keys now select items in the pane you are on.
It now uses ⌘ + Left or ⌘ + Right to move through the Launchpad panes (which was probably why it was changed IMHO)
Is there any way to change Launchpad back to the way it worked previously? I happened to like it that way and the click drag thing is so Windows.