Yea, crowds thin out, weather is great. It can easily be really cold during the day, or very warm, so you have to be prepared. It's not unusual to have 30 degree temperatures at night in the beginning of the week and have it warm up to the high 70's during the day by the end of the week.
Crowds should be rather nice, although it still is going to be busier than usual (but not nearly as packed as Thanksgiving and Christmas/New Years).
And as disney6family said, the best part is all the decorations are up!!! (although they are up normally by the week of Thanksgiving anyways). If you go you'll absolutely love it, nothing like Disney during the holidays!