Mickey's Halloween Party
is the actual
party, but there are character photo locations, dance areas (or stations, with dance floors), treat trails, etc., set up around/at the party. See
SueTGGR's map post from last year --
http://www.disboards.com/showpost.php?p=46321904&postcount=838.
I notice that the dance areas are being referred to as "parties," which I think started in the Disney Parks Blog somewhere last year. That may be misunderstood or misinterpreted by someone who thinks that the dance parties are totally separate entities from the MHP. There are no actual separate parties, per se...which is what it sort of sounds like (to me) when it's referred to as that. (And Disney may be using that term in certain places, but I don't recall seeing the words "dance party" used for the dance stations at the MHP or in the map?

I may have overlooked it on my map.). There is a Halloween party in which dancing takes place in a couple of areas. They'd be better off just saying "dance stations," to be honest!
I think that the fact that the Villains/13th Hour thing that is happening on 9/13 is tied in with something that
is called a "dance party" is confusing the issue even further this year (or it will) -- but the event that is happening on 9/13 is
not the same as Mickey's Halloween Party (it's a totally separate thing) so, for all intents and purposes, the event on 9/13
is an actual dance party in and of itself.
dnamertz --
As I mentioned in my post yesterday, I saw characters dancing with guests, with each other and with CMs. It was really cute. I saw the whole Incredibles crew at one of the dance areas. I would imagine you'd see them at the Tomorrowland dance spot.
Pirate Goofy was one of the characters at the Piratepalooza spot last year. I think I recall someone saying that Donald was there at some point too, but I could be wrong on that. I think the characters probably depend on whichever theme they go with in the area.
The more interesting characters (or, at least, a bigger variety of them) are probably scattered about at the actual photo spots than at the dance areas, I think.