Also if you are interested in attending a roadshow the 18th season summer tour is going to be announced at noon on Monday, January 7th on their facebook page. I went once, years ago, and it really is an amazing day. In the past the tickets were given by lottery so get as many people as you can to apply and cross your fingers.
If you do get picked I recommend comfortable shoes.
UPDATE; You can now apply for tickets to the Season 18 Antiques Roadshow.