I will be starting with my family of 5 (2 adults, 18, fourteen as well as 6 yr old)around December 20-27, 2010; as well as would design to outlay the lot of time in Universal Sutdios Harry Potter land. you would additionally similar to to know if you will need the car?

Nasty time to go. This is the most crowded time of year and since the HP opened at Universal is has been jammed pack.
check out site below for help. I would also check out your public library. There are plenty of books out on that area- best hotels on a budget ect. Not everything will have to do with WDW- even in some WDW books it gives info on Universal
The Super 8 on International Drive/American Way is certainly budget, but I can’t recommend it. I’m not picky about motels but this one’s a real dive. The location is awesome though for getting to Universal. You don’t have to make any left turns. There are a few other motels right there, you might want to check them out by looking at google maps near the International Drive/S. Kirkman rd. intersection. That spot on International drive has plenty of inexpensive restaurants too. The traffic can be a little intense.
I would expect you’ll spend more time *in line* for the Harry Potter section than you’ll actually spend *in* the Harry Potter section. Not trying to be a downer, but there are crowds right now swamping the place, at Christmas expect long, long waits. The park will probably fill to capacity before noon, and the Harry Potter section is only a small part of the park. A lot of people won’t even be able to get inside, no kidding.
I would recommend a car. Unless you are going to Disney and only visiting their parks, it’s quite difficult/expensive to get around without one. Most people end up renting a car after a couple of days.
Again, not trying to be a downer, I just think if folks go unprepared it can be a crappy vacation. With planning you really can visit Orlando over Christmas and have a great trip.