Hmm, I dunno if HOB would be the best way to find out or not. Could try them I suppose since they own the Gorge. Or could do a mass contacting of all bands that support taping and ask/urge them to work with the festival to allow it. I am positive on Gary Jules, Donavon Frankenreiter, The Black Keys, and Ben Lee all have taping policy's that allow it for sure. And Built To Spill, Sleater-Kinney, Cat Power, Alexi Murdoch are all probables who allow it but don't have official policy's. But I think the biggest factor would be The Roots(whom also have nothing official) since they are the supposed headliner of the festival. I have heard they allow taping but who knows, found nothing on their mess of a website including any contacts.
EDIT: They *just* posted the set times here:
http://www.hob.com/tickets/festivals/sasquatch/2004/artists/Looks like Thievery Corporation is actually closing so I am not sure now if they would be considered the "headliner" or not.
Jeez looks like most of the people I'd be interested are on the side stage....should make taping allowed just over there lol ;p
Hope we can find out before this Tuesday because I have a feeling they may offer it up on "Two for Tuesdays" again since I think ticket sales are tanking pretty big for this years show.