According to a recent interview on AMC's Geeking Out (with Kevin Smith and Greg Grunberg), Deadpool 2 writers Rhett Reese and Paul Wernick are also working on a sequel to their other big hit, 2009's Zombieland.
Here's what they said, as reported by ComicBook.com:
"That is breaking news that we're on Zombieland 2 right now...We're sitting with Woody (Harrelson) tomorrow and are going to sort of walk him through some of the stuff we want to do. All the cast is pretty excited."
Technically-speaking, Zombieland 2 has been in development (on one level or another) ever since the first Zombieland arrived. There was gonna be a sequel, then it was gonna be an Amazon pilot, then it wasn't, then someone claimed it was going to be a sequel shooting in August of 2016, and then it was re-re-re-announced as a sequel at this year's CinemaCon (via a logo reveal).
All of which is to say: it's obvious these guys want Zombieland 2 to happen, but who knows what form it might take or if it's really gonna come together this time. Sitting down with Woody Harrelson certainly sounds like a step in the right direction, but I'd be willing to bet that all involved were also approached before every previous iteration of Zombieland 2 that didn't come together.
Anyway, we're keeping one eye on this thing and will let you know if it starts taking shape for real.