Within days of X-Men Origins: Wolverine being released 20th Century Fox announced that they were developing a Deadpool spin-off, with Ryan Reynolds back playing the Merc with the Mouth. Since then we haven’t heard anything more about it, however Reynolds recently spoke to HitFix and it seems he is pretty involved creatively.
“Well, I’m intimately involved with it. We’re just trying to break a story right now and figure out who the villain is going to be and all that stuff. But, it’s going to be just like the comic books. I’m gonna have a messed up face and you may see some flashbacks of Wade earlier in his life, but primarily what you see is what you get in the comics and that’s the goal. And there is no better place to draw material from then the comics which are incredible.”
I’m assuming this would take place after X-Men Origins: Wolverine, however I think they should just do their own thing and not focus on what happened in Wolverine too much. It’ll be two or three years before we get to see Deadpool on screen, but it will be an interesting movie to follow.