Oh don't be nervous. You're more advanced than a lot of people who go. I've been to that one a couple of times. You'll meet lots of wonderful people, and see some really amazing shows. This is the first time it'll be in Philly.
I wanted to go this year because it looks like they're offering some really fabulous workshops. Alas, it's the week before Gen Con, and I'm already committed to go to that for the web series I work on. For some reason my family doesn't want me gone for that long... Well, that and the airfare alone is $$ from Arizona.
If you happen to go to the Puppetry Store while you're there, it'll be run by all of my friends! The P of A Puppetry Store is housed & run by the puppet theater I work with from time to time. :)
