I've heard a lot of people say they are planning to go for Presidents' Week this year, myself included. Park attendance has been picking up in general -- they set a record on Dec. 31, 2002 -- so I don't know how accurate last year's attendance is in trying to predict this year's. I'm very nervous about the crowds and would have never picked this week if we weren't bringing DH's parents (DILs, if that is an acronym) who are both educators.
If the week after Thanksgiving is doable for everyone in your family with regard to school and work, I'd vote for that instead. I know it's more difficult to wait 9 months instead of 2 weeks, but there are some great trade offs. The holiday decorations are up and everything is even more "magical" as a result. You may even get a chance to do Mickey's Very Merry Christmas Party while you're there. The onsite Disney hotels are MUCH less expensive that time of year. Plus the extra time will allow you to save money for extra souveniers/fine dining/whatever, and as the anticipation builds up, you will be that much more excited when the time finally comes.
The weather may also be a factor. I've been there for a VERY cold February and two mild Novembers (although I remember at least one rainy day in November). But then again, I'm not a meterologist.
Goodness, I'd better stop now before I decide to cancel my upcoming trip!
HTH, JMHO, YMMV!!!!!