The Deadpool movie's been 'under development' for a long time now, and each time we hear something new about it, it's some sort of completely useless news (such as directors or actors saying it'll happen, but never saying when) or not so useless news that fire up a spark on the matter (like the aquisition of a director no one knows) only to have that spark die out after another six or more months of radio silence. It's more than enough to make any fan lose hope altogether that this movie's ever being made.
But X Men Origins: Wolverine happened a long time ago, and since then many other good super hero movies saw the light of day (not that X Men Origins: Wolverine was good). Some of them were rated R and became even successful franchises, such as Kick Ass. So why is Fox still so afraid of making an R-rated Deadpool movie? They have an amazing script, an actor who's said over and over again he's willing to play the part, and a director. X Mex First Class was a big hit, and after the backlash on Wolverine Origins they're bound to get it right this time. It's been said over and over again that everything's set, it just depends on the studio to give the green light. So why don't they?
A more optimistic opinion might say they're waiting until Ryan Reynolds' schedule clears out, being that he's involved in RIPD and a few other projects for the next few months. Maybe they really want him to play Wade, as most of us fans do, but that's a really optimistic approach on the matter. But on the other hand, it might be a good option to make sure he's in it, because Ryan Reynolds has proven over and over again he's the right fit for the role. We've all seen his acting abilities, we've even seen him as Wade himself, and a solo Deadpool movie is the perfect one to really get Ryan Reynolds to prove himself as an actor, not only because he will portray a physically and mentally scarred man, but because the character has so many layers that can possibly be explored.
A more pessimistic (and realistic) view is that FOX is scared of doing an R-rated super hero movie. And it's completely unfounded, because it's been proven many times that comic book fans aren't afraid of R-rated movies. Just look at Kick Ass and it's success. So why is Fox so afraid of it? The Deadpool movie will have a huge fan base, possibly even bigger than Kick Ass, considering it's a much older character and possibly more well known. All of the fans are waiting for this movie, and if they really start making sure that Fox knows they want this movie sometime before Ryan Reynolds turns 50, just like they made sure Fox knew they weren't happy with Deadpool's portrayal in X Men Origins: Wolverine, it might serve as an extra incentive for the studio to green light the movie.