They were handing out cards today which said this- It says nothing about any time of the taping which means as long as you did not use your E Ticket you can go on Sunday!
Magic Kingdom
Disney Parks Christmas Day Parade Filming 2009
Due to current weather conditions, we had to move our production of the Disney Parks Christmas Day Parade filming from Friday December 4th to Sunday December 6th, 2009. However if you are available we invite you to return on Sunday December 6th, 2009 at 7am to be part of our production number. Your special one-time-use E Ticket will be valid on Sunday only if you choose not to use it today Friday, December 4, 2009.
If you are unable to join us Sunday December 6, at 7am you are welcome to use your special E ticket after 9am today Friday December 4th here in Magic Kingdom Park. Your E Ticket is not valid for fast pass or for Re Entry and as a reminder if you choose to use your E Ticket on Friday December 4th it will not be valid on Sunday December 6.
We are sorry for any inconvenience this weather-related change has caused and we thank you for helping us bring the Disney Parks Christmas Day Parade to life.