As you enter the park, you're greeted with hundreds of pumpkins lining down Main Street. In each shop you can find plenty of Disney character costumes and Nightmare Before Christmas paraphenalia.
Space Mountain was festive - aside from flying through galaxies of stars, a fiery ghost (resembling the mummy from Universal Studio's The Mummy's Revenge ride) would pop up around each bend.
The Haunted Mansion ride was obviously the place to be. The Nightmare Before Christmas had taken over the mansion, and everyone was perfectly willing to wait an hour or more to get in. The effects and puppets were amazing. And even the simple effect of projecting singing jack-o-lantern faces on pumpkins was fantastic.
At the far end of Frontierland, we stumbled upon a lovely harvest-themed area. In the picnic pavillion, you're served food out of old timey pots and drink apple juice from mason jars. There was also a small petting zoo, with goats who were obviously well taken care of and wearing festive Halloween bandanas and hats.
We also walked through an area with expert pumpkin carvers surrounded my samples of their work.
The one thing I was disappointed with though was the lack of Halloween elsewhere in the park. We only ran into a few Disney characters decked out in Halloween garb. And the commercials playing in the LA area, as well as the Disney website, promotes their HalloweenTime event as owned by the villains - Jafar, Ursula, Captain Hook, etc. Did we see any of them? No. No sign. Maybe we were just in the wrong place at the wrong time, but I was baffled by the lack of bad guys.
Overall, I really did enjoy my day. The weather was perfect, the lines for the most part were short, and we hit the Haunted Mansion twice because it was so great. I had a free pass from a volunteer thing I did earlier this year, but the general cost to get in was $80. If you're going just to go the experience of Disneyland, I think it's well worth the day of fun. But if you're going just as a Halloween activity, I'd say check out on of the other local attractions like Universal Studios or Knotts.