The chatroom opens at 5pm EST and will extend well into the night. It's not unheard of people being in the chat super super late, so even if you are in different time zones, please drop by.
meg_tdj is polling for eps on her LJ and has more information on what is planned for the night. Instead of just repeating everything, here is the link to her post:
Supernatural Chat and Event Info
I hope many of you will come. We should have a real fun time just getting together and chatting away about the show. I know I'm excited :)