Given that so many of us trim our trees and homes with the class of decorations I like to call "mass-produced collectibles", I'd like to hear something about things like Hallmark Keepsake Ornaments (celebrating their 40th year this year), Department 56 villages, Fontanini, Radko, etc. I don't know what there is to say about them, but it's interesting to see the change in decorations over the last half of the 20th century.
Could also have a segment where RJD talks about some of the Christmas specials and marathons he records annually.
Since we did one with our kids last year, maybe it would be fun to do a segment where you discuss the elf on the shelf tradition and members could discuss some of the creative ways the elf has revealed him or herself.
I can't remember if you've done something like it, but what about a piece talking about Christmas as a backdrop for something darker such as action movies like Die Hard or even Christmas horror movies like Silent Night, Deadly Night.