I usually go the last 2 weeks in June. As a surprise we are going from December 14th to the 19th. We have tickets to the
MVMCP. Any advice from anyone who has been there around this time would be great. What should we look for? the crowds? the weather? Anything worth seeing?
Book one of the Candlelight processional dinner packages (or just try to attend without one). It's REALLY a "neat" night.
Definitely make sure you take some time touring the different hotels and checking out their decorations. That, to us, was as much fun as any of the attractions...especially if you're a WDW "regular".
Make sure you see the Osbourne Family lights at MGM. They were NOT doing the music synchro when we last saw them, and I've heard they're even better with it.
Crowds in early december will be light, and will grow the closer you get to X-mas....with the days just before Xmas (like the 22nd-ish) leading up to and through New years being practically gridlock. The plus side is, if you're not "attraction commandos", there's LOTS of other neat stuff (shows, parades, street performers, etc) going on that's worth the price of admission to the parks anyway. Looking at your dates, though, you should be fine: Pretty to VERY light crowds.
The weather is typically in the mid to upper 70's, with cool nights. You can have some MUCH colder days (mid 50's) and some MUCH warmer days (mid 80's) so pack for pretty much anything. It IS typically pretty dry that time of year.