[tlasjr]

I think we won't see everyone in the first movie. I would expect around 6 members to start. I predict the following and for these formulaic reasons

Superman The idol who sees things in black and white
Batman The guardian who does what he has to
The Flash The newcomer comedic relief that has the serious moment that brings S&B together
Green Lantern They seem comminted to a second movie.
Wonder Woman They need the hot chick
Cyborg They need an African American
Aquaman possible but not 100%

no hawks, canaries or robrins.
No green arrow because of the tv show. No Martian manhunter in the first movie.

Oh and note on TheChris's earlier post that Christopher reeve movies were good but he wasn't THE Superman. If he's not why would you cite him.
The screen time of the major supermen

Chris Reeve 4 movies, 6 hours.
George Reeves 102 hours
Dean Cain 87 Hours
Gerard Christopher 74 hours
Tom Welling 217 hours.
Brandon Routh 2 hours though really he was playing Reeve, playing Superman

So if Christopher Reeve isn't THE Superman why does everyone focus on him? I own all ten seasons of Smallville and would be thrilled if Welling got the role in Justice Leauge but as it stands right now, YES Christopher Reeve is THE Superman.

You're right though, whoever is playing him better not repeat Rouths mistake and own the character themselves. It's like Bond. Sean Connery is THE Bond but don't try to play Connery playing Bond, play Bond. Routh is the Lazenby of the Superman series. ....Wow I hope Cavill isn't the Dalton.