This is already shaping up into the best superhero movie this side of the Avengers
Yeah, I'm not a big Green Lantern fan anymore - I was when I was 13, though - I even wore one of my mom's green rings about which I received no end of s**t from my relative and classmates.
Here's the basic appeal of Green Lantern compared to the other DC characters. To be Superman, you have to be from Krypton. To be Batman, you have to be rich and spend all your time training. To be Wonder Woman, you have to be a girl.
To be Green Lantern you just need to find a magic green ring from space.
As we know, who the Green Lantern actually is doesn't matter so much. Hal Jordan really isn't any better than Kyle Rayner, Guy Gardner or John Stewart.
However, I would like to see the GL Corps treated less like The Cosmic Knights of the Round (and really really big) Table, and more like the Space Marines from Aliens. In the comics, I'm fine with the chivalrous and noble ideal heroes of the corps, but in a cinematic version, I'd much rather see this as a kind of military force that often makes mistakes and is, at times, just the lesser of two evils. That they are far from perfect just like Hal or Kyle or whoever gets the ring is.
And it gives Sinestro a bit more justification for opposing them. In the end, he's an opportunist using the Corps' faults for his own benefit, but it is those faults that give him any traction at all in the universe.