I grew up more of a Marvel kid as well (and continue that way today), but I do read both universes these days. Aside from Batman/Detective, I don't think I had a DC comic until I was an adult. I can sort of see the point of the universe cohesiveness though, and although I hate to use the term again, but "grounded" quality of the MU does help a bit when translating to live action I think. Batman works great, as he is more of that type of character too, but it might be difficult to see the others. I also agree that WB/DC missed the boat with Green Arrow. He is arguably much better known than Hawkeye (prior to the Avengers), but now most non-comic people are going to think he's a "rip off" of Hawkeye.
That said, even being more of a Marvel person, I'd like to see more DC stuff make it to the big screen as well. I know they've already confirmed a "reboot" of Batman after the Nolan trilogy, and I guess that is expected. I will say, for as amazing as the Nolan movies have been (and they are), if we do see a re-do of Batman again I wouldn't mind something that allows for things like Dick Grayson/Robin, Batgirl, and some of the other less-dark/grounded aspects of that universe. My favorite interpretation of the Batman world has always been the Animated Series, and I'd like to see something similar to that tone for the movie universe if they are going to move away from the current darker take.