36 keys!! wait... are you macro-ing any of those? are they all on several action bar? and when you multi-box boost, im guessing you're going to be using the lock as the main?
Yeah, my 'lock is my main and I have three sets of spells/macro's/abilities mapped to three throws of 12 hotkeys: row 1 (nomod), row 2 (shift), and row 3 (alt). Its from my pre multi-boxing days and I'm used to it for PvP, etc.

Obviously when multi-boxing I want to use a different set of main 12 (1 through "="). But, I'd like to be able to revert back to my original bar/hotkey combination when playing solo. Still trying to figure that out.

Bartender4 is being built for WotLK. You can read the developers thoughts http://forums.wowace.com/showthread.php?t=12513&page=65.