For the most part, weather has agreed with the park, this year. As I recall, last year, in addition to a major ice storm, torrents of rain fell on many weekends (Remember how long we waited as they postponed the parking project due to weather.). I think this may have contributed to smaller crowds for many weekends in '08. I also remember being there with the largest crowd in park history, last Christmas season.
I really believe the weather is probably the primary drive in crowd fluctuations and not the economy. Poverty studies consistently produce data that shows entertainment is more and more important to families who can't afford necessities. No need to get into details, but I wonder if HFE is aware of this fact or if they simply react to the economic situation. It's a tricky game to master.