I can only tell you of my personal experience this year----it was more crowded than I ever thought it would be but not as bad as summer/holiday crowds.
I stayed on property at POP Century and was told by 2 different CM's that the resort was booked to capacity. We went into MGM one day and had to leave because it was overcome by cheerleaders. There was some cheerleading competition, as well as a high school band competitions going on. My friends and I stopped for pizza at Pizza Planet and witnessed some of the rudest behaviour by cheerleaders. Holding places in line for 20 of their friends....cat fights.....that sort of thing. Not all the cheerleaders, by any means, were as nasty as the crowd we bumped into at Pizza Planet.
Some attractions were walk-on, while other times I saw 30-40 min waits. I was there Feb 11-14, 2005. I've been to WDW Jan 30-Feb 3 or 4th (twice) in the past and it seemed much less crowded.
I'm not sure these cheerleading/band competitions occur every year at this same time though. I was caught off-guard by it.