Warning - The following post contains the ramblings of a horror fan who thinks he knows everything - You were warned!
I can agree with the idea of a wolf-man house; a classic Universal monster being revamped for a new movie. It makes absolute sense to cash in on it at any opportunity, and besides, isn't there usually a house themed on a recent (or semi-recent) film?
Saw, on the other hand... I just can't get behind the idea of Jigsaw running the entire event. Think about it; there is a sense of intimacy in Jigsaw's "games" that I don't feel can translate to a large scale event like HHN. If you spread the guy out over the whole park, his "tests" lose their magic. Besides, eight torture houses wouldn't be entirely interesting. Now a show or single house could EASILY work, though.
To me, it only makes sense that there will be an original Universal Icon acting as a mascot for the event. Even when Freddy, Jason, and Leatherface were center stage, Universal still used Jack to advertise HHN. On top of that, an Icon that is ONLY associated with HHN allows the studio to create a new story to tie the houses together without having to hold up to any standards of any licensed properties (i.e - Jack brought the NLC characters to his carnival).
That said, I would love to see the return of the Eddie Sawyer character (the guy who was supposed to take over the park but was turned into Jack's brother because of 9/11 attacks). The idea of a fan gone too far could translate into a park-wide event very easily. Just rework him a bit and - BOOM - new event Icon!
But that's just my opinion.