We did it in early December 2007. It was sold out the night we went. It was crowded on Main Street, but we walked onto every ride we chose to ride that night. We also walked right up for our cookies and hot chocolate. (I was sure we'd have to wait forever.) There were lots of characters around for pictures, too.
The parade and the fireworks were incredible... and I do think, overall, it was a nice experience. I don't know if it's "worth" the money, but we had already spent it by then -- and we had a great time.
I would be willing to do it again, but I will wait till my kids are older. They were 3 and 7 at the time and they got tired (and we left) several hours before the party was over. I am sure we could have gotten *lots* of extra rides in if we'd stayed till the end.