I've been reading some of the comments against the R rating and I had to give my two cents. First off I feel that calling Deadpool a "Hardcore Spider-Man" or basically a looney tune is a disservice to the character. I know he was portrayed that way heavily during the final half of Way's run, but the current run has restored him to his proper character. As others have said, Wade Wilson is a broken character. His antics are not only a reaction to the severe trauma both physical and emotional, but his attempt to create a his own reality because he rejects the actual reality around because life has been so cruel to him. There is a scene in the comics where Deadpool while at weapon X repeatedly tries to kill himself but fails due to his healing factor. Not only is the world cruel to him, but it never grants him his escape. I don't think that sort of desperation can be conveyed if they are trying to appeal to families.
Also the argument that Deadpool was originally intended to be an all ages character is honestly not a great argument. When Stan Lee created Daredevil he was more of swashbuckling hero. However under the pen of subsequent writers, most famously Frank Miller, Daredevil evolved into a gritty, psychological hero. Should the upcoming Netflix series, which is getting praise across the board from critics be condemned because it doesn't uphold to Stan Lee's original characterization of Matt Murdock? Spider-Man and Batman are probably the two most beloved heroes by both adults and children. Under this flimsy argument those two characters should never go dark due to their overall marketing appeal with children. However one of Spider-Man's greatest stories is the very adult Kraven's Last Hunt and the final chapter of the Arkham series is going to be rated M, the equivalent of rated R. Why? Because it is what serves the story trying to be told, which is what the Deadpool film is doing.
We should be grateful that the creative forces behind this film are being given free reign to accurately adapt our Merc with a Mouth. The argument being presented for a PG-13 film also seems to be in favor of Deadpool being another superhero film off the assembly line. I don't want that. I want the film to be as unique to other superhero films as Deadpool is the other heroes that inhabit the Marvel universe. Deadpool being popular shouldn't dilute what made him popular in the first place.
t:
hasnt even come out but this movie is a game changer already 
