I'm hoping they find an African actor with an authentic accent. Imagine how Africans would feel if someone from another country (or continent) were portraying a hero of their native land. It would be like if Hugh Jackman weren't Canadian, or Andrew Garfield weren't American.
I hope they do some redesigns on Cap's uniform. Looks like he'll be going the "Super Soldier" uniform route for Cap 2, but I'd like to see him return to the usual Red, White 'n Blue for the Avengers 2. However, I'd like to see it armored up a little.
Something like the Marvel NOW version of Cap's uniform would be awesome:
Quicksilver can be anyone in my opinion. A decent actor who can play up the Mutant Superiority bit if they go that route with the M-Twins' attitudes.
Scarlet Witch. She can end up being a key player in a future movie if they go all Avengersisassembled. Why not Eliza Dushku? She'd be awesome. Or we can steal Anne Hathaway for Marvel!
I'm guessing they'll go with that one British chick they keep mentioning.
I don't think there is any cooperation or collaboration going on here at all. There is just a situation where they both have legal rights to the characters, one as Avengers and one as X-Men.
I doubt there is any conversation going on between studios, just Fox reading about Whedon's plans for Avengers 2 followed by a knee-jerk reaction shoehorning Quicksilver into an existing X-Men script that is getting more and more crowded and rewritten with every passing week depending on Singer's whims and the availability and interest of the actors.
I wouldnt put it past Singer to try and needle Whedon or upstage him in this small way.
Theirs leeway in casting and adding characters on the fly in movies like this depending on how substantial the role is.
Singer doesn't get the benefit of the doubt.
From what I understand, whoever uses Magneto's kids first in a film gets the rights to them. So it certainly seems like Fox is throwing them in for little more than a cameo just so Marvel studios can't have them. Otherwise Marvel ought to be able to use "Avenger" Spider-Man, Wolverine, etc if the rights worked differently.