Everytime a sci-fi movie is a hit and therefore a sequel is expected, fans are speculating about the possibility to have Summer Glau play in it; for example, some suggested that Summer replace Sigourney Weaver in Avatar 2, or Angelina Jolie in a Lara Croft sequel, or Summer as X-23 in Marvel comics the X-Men, or more recently as Annie Cresta in The Hunger Games sequel "Catching Fire" (see blog post
Now that Joss Whedon's The Avengers exceeded all expectations and that we are promised a sequel with a cosmic villain, some are expecting to see the Avengers team take on Ultron because that would also mean the introduction of Henry Pym and Janet Van Dyne (aka Ant-Man and the Wasp!), ideally played by Firefly alumns Nathan Fillion and Summer Glau.
Read more about supervillain Ultron
and superheroine The wasp
A little casting buzz history :
Back in September 2008, Eva Longoria was spotted near Marvel offices carrying a stack of comics but she later denied the rumors; in September 2010 Mania reported that Morena Baccarin was seen "visiting a comic shop and purchasing "a bunch of Avengers comics. Our tipster further said she was asking the store workers to specifically point out comics with the Wasp in them.”
And now it could be Summer Glau's turn!
UPDATE : It looks like Joss Whedon is looking for another female role on The Avengers
sequel, why not Summer?
Article : 'The Avengers' sequel: Should another female join the superhero squad? at EW
Here are a few images on the same topic :