My predictions for the 2013 mazes:
Carnival will return again as a paid maze, with more emphasis on creating a finale. With the amount of money that was spent on it this year, I'de be extremely surprised if they got rid of it.
TOTT will return again as a free maze. I'de imagine they'll change the tag-line from 'what lies within' to something else, overhaul it a bit. However they'll keep the strobe finale and many large theming pieces. It works brilliantly as it is, just needs freshening up.
The Sanctuary will return again as a paid maze. Considering the money invested into it this year, the well produced videos, brilliantly thought out theme, and rave reviews I'de be almost certain it will return. Maybe a slight change in story to reflect the opening of SW7, and some teak to the ending to get people running out the door.
The 'scare-zone' will return in one form or another. I'de love to see Zombies! return and be given a bit more attention for next season.
Instead of any additional attractions next year, the park need to sort out the lighting. Get the place back to like it was in 2010. Coloured lighting and smoke would make a huge difference to park atmosphere. Towers already have a fantastic backdrop for a Halloween, show it off!
To spread the Halloween event across the park, It'd be great to see Duel: Live return and an additional scare-zone on that side of the park next year, however I'm fairly certain this won't happen.
For 2014 they should invest in another maze. With the addition of the lodges they could potentially bring back the field over at the hotels, make it free to hotel guests and paid to park guests. Though it's debatable as whether they'd do this, park mazes are bound to make more revenue.