Personally, I can't stand the DC Universe, the only two characters I like are:

-Batman I love because he is just awesome (But at the end of the day he's just a well trained man with a lot of money ).
-Mr. Manhattan because, well... in my mind, if there was ever to be a 'God' he is the closest being to being one (That guys powers would make even Apocalypse tremble).

Now, the only thing that has me curious about this movie is Ryan Reynolds.
The guy is an awesome actor with a lot of range and comedy comes naturally to the bloke. I loved his portrayal of Deadpool and am looking forward to that movie greatly.

I can't say I know much about the Green Lantern apart from the ring being their source of power, all I can say is I hope that it's nothing like that supposedly 'Super' man who's allergic to his own planet ... The Hulk would totally own that guy!