I have gone to WDW twice in the last 2 years (09, 11) both with friends. The first one, I had to drag out of bed every morning, and the second one, she was up at 5:30-6:00am very morning!!
I am going solo to
Disneyland in 12 days. I am looking forward to sleeping in and getting up when I want to
I do eat at resturaunts by myself and will go to movies by myself (usually Sunday afternoons) so I think I will be okay. I also live alone and have been single (by choice) for over 3 years, so being alone doesn't bother me. I am a little worried about long lines and having no one I know to talk to though.
If you do end up going and you don't enjoy yourself, then don't go solo again. You will never know if you don't try