Recasting the iconic three? Huge gamble.. it did pay off with the new Star Trek movie but that's like lightning in a bottle.. extremely rare.
Especially finding a new Han Solo could be tricky.. he brought so much to the role. Now that i think about it.. Nathan Fillion might be open to the role
They'll just go to the Avengers well. Chris Evans as Luke, Cobie Smulders as Leia, Robert Downey Jr. as Han.