Here's my take on each of these:
Fantasyland Extension: This I'd say is the most likely announcement, especially since the public knows what the plans are, or were, because of the leak. Hopefully those plans will become official and maybe we'll hear about a MK version of Blue Sky and a timetable for the expansion.
New E-Ticket/Land for Animal Kingdom: At E3 expos (aka Electronic Entertainment Expo), game publishers often throw in that surprise announcement that leave everyone talking at the end. This could be that announcement for D23.
Imagination 4.0: I think this will be announced soon, mostly because that pavilion is pretty much deserted most of the time. It needs to happen, and D23 would be a good place to reveal the plans.
Pixar Place Expansion: I think this may be a ways off. I think it will happen, but DHS has already gotten two new attractions in 2 years. I'd say a more likely DHS announcement would be a replacement for Sounds Dangerous.
Star Tours 2.0: Comic-Con would have been a good place to announce this, but D23 would work well too. Everyone knows this exists, it's just a matter of time as far as when it will become official.
Sorcerer's Hat Officially Removed:This doesn't even need a national announcement. Just remove the hat and be done with it!
Confirmed New World Showcase Pavilion: Hmm, I'd say this is the least likely announcement, especially since there really hasn't been anything brewing on that front for a long time, but I'd love to be proven wrong...