The rumors have been dismissed by Dan Houser, co-founder and creative VP at Rockstar, during an interview with Variety:

"We’re not per se against moving properties between different media but for GTA it just seems so perfect as a game. You lose a lot of what makes it what it is if you move it into being, say, a movie. It just never seemed interesting creatively."

"We’re not really interested in them doing it. If and when we wanted to do that kind of stuff… One of the things media struggles with about videogames that I’m very clear on in my mind is that it’s a team thing. One of the things I’ve always found weird about movies is they’re like, “Here’s a movie made by hundreds of people and let’s talk to one of the actors.”"

So, no dice, Uwe Boll fans. Speaking about the game itself, Houser stressed out that the latest installment in the GTA franchise is a huge step forward, similar to the one from the second to the third game in the series:

"What we wanted was the feeling when you saw “GTA 3” after “GTA 2.” The feeling when see “4” compared to “3,” hopefully it’s not difficult to see differences. […] We’ve got this city that feels alive. It has all these activities you could never have gone and done in that amount detail."