From EW:

Stallone said the superstar-summit scene takes place in a church, where Willis’ nasty antagonist has summoned Stallone’s macho mercenary to finally meet him face-to-face, take measure of him, and possibly hire him for a death-defying mission. But just as the meeting gets under way and smartass smalltalk is made, in walks another killer-for-hire — Stallone’s longtime rival, who Willis has also invited to this job interview: Ah-nuld.

“Bruce says ‘Well, there’s one other person I want to talk to before I hire you,” says Stallone. “And then Arnold, who plays my old rival, walks in. We have a history together. And we go back and forth and I tell him that I should have shot him a long time ago when I had the chance. Then it goes on from there. And here we are, the three of us trying to man up to one another, playing off of who we are, using our baggage in this one scene.”

Stallone says that big scene with Willis, Schwarzenegger, and himself would amount to more than a cameo or a stunt in the final cut of the film. “It’s probably going to be about 5 minutes of screen time.”

There’s gotta be some way I can see this movie early.  I just can’t wait till August 2010.  Think Sylvester Stallone reads our site?  Ha!  Of course he does!  Give me a call Sly, let’s figure something out!