I suspect it's easy to fear the worst about being alone at Disney. But think back about going to places by yourself that are more geared for "groups". Like, for instance, going to the mall. Sure, it's fun to go with others and window shop and have coffee while you chat and watch the crowds go by. But what about the times that you've gone to the mall by yourself? You get to ditch into stores that you normally wouldn't if someone else were with you. You get to go at your own pace. You get to go your own speed through the music store, looking through every Boston CD (because no one else would waste their time doing this!). You get to go smell every type of hand cream in the bath store, even though you have no intent on buying any.
My point is, so it is at Disney by yourself. Admittedly, you must first like to be with yourself alone before you ever go. But I suspect the whole event is somewhat like going to, for example, the mall by yourself. While at first it doesn't sound like a fun event, but once you do it, you find it's pretty cool to get to go where you want when you want and have no one else dictating your schedule.
And like the "alone" mall trip, you get to do lots of people watching. At Disney, you'll get to watch other families and adorable children as they discover the Disney wonder and magic, as opposed to corraling your own children.
The fundamental, however, is you have to like being with yourself alone and being your own friend first. Then I think it's lots of fun and much easier.
Good luck!