I'll be up there from Dec 11 to Dec 15 solo...I do the unofficial 'fringe' Mousefest visit, and this'll be my third time. I have never registered for Mousefest or gone to the main Saturday event...but I thoroughly enjoy tagging along for some of the photo walks and other gatherings that are open, and love traveling solo at that time of year. I actually go to Disney 2-3 times a year solo, and another 2-3 times a year with family and/or friends. It's nice to experience Disney both ways - with a group of family sharing and enjoying, but having to try to be more organzied and mixing everyone's preferences together for an all-purpose compromise that works best for all...and then on your own, where the only schedules, desires, rides, foods, events, or timing that has to be adhered to is your own. As Willcad said, it's total and complete freedom. Sometimes, I even have friends or family who WANT to come with me, and I tell them "sorry...this trip's SOLO ONLY!".
I'm usually following around Tim Devine's photo walks when they're scheduled, and maybe a gathering here or there - and the rest of the time during Mousefest, just relax and take things at my own pace. So maybe I'll bump into some from this thread too!