We were at The World last December (2004) the first week. Regis and Kelly taped on the weekend, so we avoided MK then. I believe that was Dec. 4th and 5th. We went to
MVMCP on Tues. Nov. 30. Honestly, I would not pay for that again! It was VERY crowded!! We were at MK during the day also, and got to do everything we wanted with hardly any waits. Then the MVMCP starts and the place is a madhouse! I for one do not like to have to line up for parades and shows 2 hours ahead of time. The whole night was spent waiting for the Night Before Christmas show (1 hour and 45 minutes, and still BARELY found a seat) and the 2nd parade (stood in our spot for over 1 1/2 hours, and then had people cram us over at the last minute!!) By the end of the night, I was so disgusted! Wasn't having a very "magical" evening.
My advice, Save your money. You still get the Christmas feel from the parks during the day (beautiful decorations!!) and the lines are almost nonexisitant. Spend the MVMCP party night at Epcot and enjoy Illuminations and save the aggravation of the HUGE crowds at MK.
I can honestly say, that Regis and Kelly taping had no effect on crowds for us. Like I said we, did MK during the weekdays and spent Sat. and Sun. at the other parks. I didn't even hear anyone talking about REgis and Kelly, it's like they weren't there!
Whatever you decide, have a great trip!