Hey, Sherry! We are once again playing with the idea of returning to our beloved
Disneyland to celebrate Halloween (Early). What do you think the chances of them returning it to Calif Adventure? Wouldn't it be cool to have Carsland available to just the party go-ers? Maybe next year?
If anyone is thinking about going, young and old, it is a blast. You score at least 5lbs of candy a person without trying. My tried and true suggestion is to: Take a backpack to empty your treat bags into. It was so worth it as we didn't buy any candy for Halloween. And we had such a good time DMIL hopes we make it every year!
Love that your "Super-Thread" is still going, Sherry. Here's to hoping for dates and prices soon.
Later,
Sue
Helllllllllloooooo, Sue! 
It's great to see you again (well, not actually 'see,' but you know what I mean!)!
First, about the Superthread... Any Superthread on any major Disneyland subject or sub-topic (Fantasmic, World of Color, Grand Californian, Disneyland Hotel, Christmas time, Halloween Time, etc.) is intended to keep going, year in and year out. These Superthreads are intended to be permanent threads with all kinds of info, photos, updates, etc., so that people can easily access them year-round while doing research for their planning. (This is why we have them permanently planted as links in Mary Jo's main Info sticky thread at the top of the Disneyland forum page.)
Now in the case of Halloween or Christmas, because those seasons have different dates each year, I will alter the titles of the Superthreads to temporarily include the current year's dates, and will try to include anything 'new' somewhere on the first page - like if there are new highlights or new attractions that are significant in some way. Then, once the seasons have ended, I remove the dates and the thread goes back to being the normal year-round information/photo Superthread!
Okay, let's see...about your DCA/Halloween question...
But let me digress and go way off-topic over to the holiday season for a moment, before reeling it back in to Halloween Time.

I have had a strong hunch for a while that "they" (Disneyland/Team Disney Anaheim) may eventually try to throw a
Christmas party in DCA.
Why do I think that? Well, I have no doubt that "they" will want to stage a Christmas party at some point down the road since the Halloween parties are so popular at DLR, and because the Christmas parties at WDW are so popular.
The problem (as I see it) with having a Christmas party in Disneyland park itself is that, suddenly, things that have literally been available to the general public for years and years (snow falling on Main Street, holiday fireworks, holiday parade, etc.)
could possibly be taken away and become the dreaded "party exclusives." This will, no doubt, infuriate the longtime holiday visitors who have been enjoying these things every holiday season with their regular tickets/Hoppers/AP's. There will probably be quite a bit of backlash.
In the case of making the Halloween Screams fireworks exclusive to the Halloween party a couple of years ago, it was really not that big of a deal because those fireworks had only been available to the general public for one year (in 2009). It wasn't like they had been a longstanding tradition to which people had become attached.
The holiday season festivities in Disneyland, on the other hand, are longstanding traditions.
So...how could Disneyland Resort pull off having a Christmas party without inciting hate mail from people who don't want to pay for separate tickets to enjoy things they have been seeing for years?
Have the Christmas party in California Adventure, and throw in some brand new things that no one has seen or gotten used to yet! (At least, to start it off.) This would be the prime opportunity to begin an all-holiday version of World of Color. Make that the signature party event to lure in the guests. This would be the time to break out the Mr. Potato Head Christmas songs over at TSMM (which supposedly were recorded years ago). And, for pete's sake, add in some more holiday decorations around DCA - which it desperately needs! Keep the decorations in A Bug's Land and add in the rumored Cars Land decorations we have heard about.
Back to the subject of a Halloween party... If TDA were planning to have a holiday party in DCA at some point, it is possible that they could have a Halloween party there again too. For the last few years, pretty much all traces of Halloween Time have been removed from DCA while the billion dollar construction/makeover work has been going on. No more Candy Corn Acres. No more Halloween-themed music at the entrance. The candy corn CALIFORNIA letters were gone long ago. All they really had last year was Duffy's photo spot (with pumpkins as a backdrop).
If ever there is to be a Halloween party at DCA, there has to be a signature event...something exclusive to DCA that will pull people in. They could do an all-Halloween World of Color. They could whip out the Mr. Potato Head Halloween banter (which was also supposedly recorded years ago). They could put some spooky decorations in Cars Land and A Bug's Land. Stick those giant candy corns from Candy Corn Acres somewhere in the park!
I have not been following any reports (if there are any) on the possibility of the Halloween party returning to DCA - this is all just what has been floating around my mind for a long time!
Personally, I have liked the Halloween parties in both parks, for different reasons. I think that having it in Disneyland gives it a certain vibe and beauty that was not there at the party in DCA. But having a Halloween party in DCA would really serve as a way to bring DCA back into the Halloween festivities - from which it has been separated for too long now!

But I think it would most likely not happen this year. If DCA is to ever see a Halloween party again (or a Christmas party in the future), my guess would be that it would not be this year, and that it would be next year at the earliest, if not later.