Avi Arad was interviewed by MTV and spilled his guts on more projects than I really believe will make it to the big screen. There’s really no point to rehashing it here, there’s a nice summary over at RopeofSilicon.com.
He mentioned X-Men 3, Magneto, Wolverine, Ghost Rider (vs a giant tidal wave ), Spiderman 3, Captain America (think: Back to the Future), Silver Surfer, Thor, Punisher 2 and Iron Man.
Sounds like on Iron Man a complete script rewrite is being done by Nick Cassavetes, who has met with Arad several times to discuss the film.
Much more info at the link above.