I took my family to WDW in January 2001. We bought annual passes because we were staying on-property (as DVC members tend) for just under three weeks. The $aving$ for this are, I think, obvious.
Mid-year, we decided to return in December (just 7 days -- yes it's still November; long story) and stay for two weeks (that has magically become three weeks -- again, long story). We decided to return in December to get "one more use" out of our annual passes.
Because we have borrowed so many DVC points, we expect that we won't see WDW for 2002. Therefore, we won't renew our APs due to timing and Disney's AP policies.
Of couse, my wife is asking questions like "How are we going to go an entire YEAR without going to disney?" But that is not part of an AP discussion.