Glad I'm not the only one waiting on something like this! CueList looks pretty sweet, although I see why Support feels like it'd be a huge undertaking
I think the easiest way to bridge the gap would be to allow toggling between active buttons with arrow keys (so "Next" is either down or to the right).
For any programming-minded users, it looks like AutoHotKey might be able to make something like that happen with this Cycle code:
http://www.autohotkey.com/board/topic/83329-cycle-easy-automatic-cycling-through-a-list-of-elements/.
By setting each button trigger to a sequential letter of the alphabet, and then running AHK in addition to Lighting Controller, a single "Next" or "Go" button can type a different letter of the alphabet on each button press. It'd be a pain to rearrange buttons (since each trigger would have to be remapped), but for simple shows it may be a nice workaround.