Firefly and Serenity star Summer Glau is up for the part of Kitty Pryde in X3 and Joss Whedon recently comented on that rumour as quoted below:
"Summer did read for Kitty in X3. I know because she called me and mentioned she was going to and did I know anything about the character (there were no 'sides' to study -- they had to get them when they came in). So the girl I turned into sort of a superhero in my movie was going to read for the character that most influenced ALL my girl-heroes, Kitty Pryde. Karmically funky. Anyhoo, she called me after and said it was very emotional and kind of like when she read for FIREFLY, she just got into a very intense groove. She started telling me about the scene she read and that's when I realized WHY it was kind of like she read for FIREFLY. 'Cause (as you may know) it was a scene I wrote for Astonishing X-Men issue #5. I assume they just didn't have sides ready and used that but this was like a karmic moebius strip, it was just too folded in on itself. In this time of odd, I turned to beer. (No I didn't. Stay in school.)
I don't know what the X-peeps are looking for -- or even if that other girl has really dropped out -- but for my money, Summer would make a wonderful Kitty. (And I don't say that lightly.) As long as it doesn't interfere with SERENITY II: RICARDO MONTALBAN'S STILL PISSED -- or, much more importantly, SERENITY III: SO VERY NUDE."