I'm somewhat surprised that he landed this part, given that he's already played 2 Marvel characters, Hannibal Smith in Blade Trinity and Deadpool in Wolverine. Then again, for all the talk of a Deadpool spin-off, I'd lately been thinking that it was looking as likely as the Nightstalkers (Smith/ Abigail Whistler) spin-off that was supposed to come out of Blade. So perhaps it's not that surprising, though I assumed that if RR was to play a DC hero, it would be The Flash. Wonder if this 'defection' will land his Missus, Scarlett Johanssen, in trouble with her Marvel employers for Iron Man 2?!
I don't really know much about Green Lantern but I've liked Reynolds since seeing him in Blade 3. He has charm, charisma, comic timing and, let's face it guys, a superhero physique. I liked Bradley Cooper in The Hangover but I haven't seen him do any drama or serious roles, so I think RR is a better choice. Jared Leto I could also have lived with. I'm glad Trousersnake didn't get the role, though I understand that he was actually pretty good in Alpha Dog.
The other plus about Reynolds is that he is a comics fan, so hopefully having seen what went wrong with Wolverine, he'll perhaps be able to sort out the cheesiness that Jackson Archer reckons plagues this script.