The way they've done it in the past, and like Rowan said, they might make changes for this year, is that for about the 1st five minutes of the panel, flash photography is permitted, but after that - it would be in your best interest to have one or more of the following:
* high speed film - 800 ISO or higher - in color, 1600, I think, is as high as it goes; b&w goes to 3200
* a manually adjustable camera - you can set the aperture and shutter speeds manually and let in enough light that a flash isn't necessary
* a LONG lens - preferably with auto-focus - that way you can fire off the shots a bit faster and don't annoy the ppl behind you as much
* a sweet digital camera that lets in a lot of light
* the good fortune to sit in the front row -- which is usually, mostly, reserved (I think), so good luck there
That's how you can manage to take photos w/o a flash and still have them come out well...
for examples -- take a peek at my photography page --
Photography by Highlander II -- the Gatecon photos taken during the panels were all taken w/o flash -- I always have high-speed film and my long lens - plus, a wide-open aperture and sometimes I slow down the shutter speed. (if you want more explanation on some of this - maybe we can start a 'how to take photos w/o a flash' thread...)
As far as I know - unless they change the rules - the only photos and autographs that you MUST pay for are the organized photos taken with the actors in the photo room by the Gatecon photographers (ie: Richard and Fryn and whomever else they have working on it) and any autographs beyond the allotted 2 --- generally speaking.
Photos of guests that you take in the lobby or during panels or auctions are fine - as long as they follow the guidelines explained before the panels begin.
Also - and, again, this might change - during the auction, I believe, you ARE allowed to take movie-photos -- but ONLY during the auction.
The reason they don't allow video during the panels is because they film them for the Gatecon DVDs - so, no panel filming.