Digital Spy has some information concerning IT 2.
According to actor Bill Skarsgard, IT 2 will be
“I think the right way to do it is to make that movie actively different, I think there might be worth exploring sort of the psychological aspects of horror, but also maybe the sort of cosmological existence of this being. What is he, and where does he come from?”
“It’s hardly answered in the novel. I mean, it’s very abstract. And I kind of like that. IT could be almost a sort of surrealistic psychedelic trip if you go into the mind of Pennywise”
“If you’ve read the novel, you know that they do actually go into his mind. Or they go into this transdimensional place, and they sort of beat him in this place. Which might be interesting, what that place would be, and what would it look like.”
This is a good amount of IT 2 information to begin imagining what it will be about!