Also, my guess is that a lot of folks probably use this feature with no speaker attached (and listening through headphones).
I'm not sure why that would matter. If I were using headphones instead of a cab, I'd still want to not get a *pop* when I plug/unplug the cable from my MP3 player.
But, I am curious about the usage. How many folks that have a mM are using the headphone out?
I have had a micro head (Promethean) for something like 5 years now. I use the Aux In a LOT. I use it for my personal practice and I often use it at band rehearsals so the whole band can hear a song we want to play. I have never used the headphone out. The Aux In and a cab with a tweeter is kind of like having my own little personal/portable PA system.

. Anyway, welcome to Talkbass!