Can we have a John Constantine movie, please?

"All His Engines" (2005)
As Constantine should be

A couple of days ago I re-watched "Constantine", the 2005 movie starring Keanu Reeves and Rachel Weisz. As a fan (and collector) of the Hellblazer comic books I was very excited when news of a film based on them emerged, and very disappointed when I got to see it. Following its release it recieved mixed reviews, coming out with an aggregated score of about 5 to 6. in my opinion that's about right. Once my outrage on first seeing the movie (John Constantine as a shotgun toting American? WTF!?!) had lessened, I was able to watch it as a film in its own right. If you disconnect it from the comics (as the film-makers seem to have done) it's basically an ok film.
In my opinion that is a very sad thing.
If you don't know what I'm talking about see the very good wiki entry here.
John Constantine is a complex, flawed and quintessentially british (cynical) antihero character with a large fanbase. The world he moves in is intriguing and sometimes spectacular. The interaction between the two can be haunting, funny, frightening and, always, engaging. In short, a John Constantine movie has the ingredients to be one of the best films of all time (and that's without even touching on some of the other interesting characters in his world). John has been voted the 3rd greatest comic book character of all time (link) directly behind Batman and Superman. Look what they managed to do with Batman in the Dark Knight - by staying faithful to the character of Batman (and, admittedly, the Joker), whilst trying to give the film a feel of realism, they made a film that blew people away. It's a simple formula (and one they're now trying to apply to Superman and Spiderman) so surely it makes sense to apply it to Constantine?