HI! Well...we were at the Taping of the Xmas parade this past year. And if you want to be called upon as an Extra for the Taping, you submit your name to Disney (somehow..sorry don't know much on this..you will have to ask around on the boards.) But you submit your name, Disney will email you back if you get accepted and you are in a slot to stand there for 4 hours while they tape sections of the parade. However...we did not do this. We walked into the park like normal that day and watched a bit from the sidelines as passersby..we saw Regis and Kelly, right when we walked in..and we saw the floats going down Main street and an annoucer on the loud speaker saying.."okay, everyone remember its Christmas Morning..." lol
It was cute, but I don't think the crowds that weekend were worth the muss and fuss of it all. IT WAS PACKED! The WHOLE PARK. Not just main street. So if you are going that week anyway and you want to stop by for a few hours to see what you can of the parade being taped, I would reccomend, otherwise, I would STEER Clear that weekend!
Good Luck and have a Magical Time.