In addition to my massive Star Wars nerdom, I am a huge DT nerd, complete with a Roland tattoo that takes up half of my right arm.
I've always been of the opinion that they should not make the DT into movies, because it would suck, it would be nearly impossible to do, and because it wouldn't make any money. Sking's work don't translate well to film, and the Dark Tower is so much about visions and dreams and history and weirdness, it would be a bust.
There are elements that would be awesome - the Battle of Tull, the lobstrositeis, Roland's ventures into NYC, most of the plot of Wolves of the Calla (which I'm re-reading now), and especially the tale of Wizard & GLass with Roland, Cuthbert, and Alain in Mejis, but on the whole, I hope they never make it.
And Matthew M. could be a great Flagg/Marten if he really busted his ass for it. Not sure who I would choose as Roland at this point. They've thrown out Aragorn, and then Javier Bardem, I rather like the way Daniel Craig looked in Cowboys & Aliens, but Roland has to carry so much of it because he's alone so much of the time. Clearly Kathy Bates will be needed for Sylvia Pittson, but other than that, it's so daunting an idea.
I'd be cool with it if when HBO is done with GOT they made it into a TV series, but otherwise I never want to see it on screen.