Hi everyone,
I'm planning an eight day visit to DW in December for my 40th birthday and I'm tentatively shooting for the 11th through the 18th. I figure that gives me a full weekend and a few (hopefully) less crowded weekdays. I read some things that said the 7-13 week would be the least crowded of December, but I want to have the 16th in the park since that is my actual birthday. Any thoughts as to crowd size that week? THANKS!

Generally speaking, the first two weeks or so are some great weeks to go. After that, the crowds will start getting a little more crowded up until the holidays.

I have been at WDW during the dates you are looking at and if history be a guide, you should still have days with lighter crowds, especially the weekdays.

Of course, you will be there around MouseFest, so that will make it even better. :)