No actress has ever played Kitty "Shadowcat" Pryde in a live-action X-Men movie more than once. In the two X-Men movies she was played Sumela Kay and Katie Stuart (who had about twenty seconds of screen time each); and in X-Men: The Last Stand it was Ellen Page, who finally gave the character a chance to be more than background. Now that director Bryan Singer is bringing back the trilogy cast for X-Men: Days of Future Past, however, he has broken that streak - as seen in the above set photo.
This image is just the latest that the filmmaker has posted on his Twitter feed -arriving with the message "Hello, Kitty @EllenPage #XMen #DaysofFuturePast" - and this is actually a two-for-one considering you can see Iceman (Shawn Ashmore) standing with Page. The details on the Shadowcat costume are fairly minimal, though it does look like she's wearing some kind of armor on her forearms (why an intangible mutant would need armor is kind of a mystery, but let's just roll with it).
In addition to Page and Ashmore, the next X-Men sequel will also bring back Sir Patrick Stewart, Sir Ian McKellen, Hugh Jackman, Anna Paquin, Halle Berry and Daniel Cudmore, as well as First Class stars James McAvoy, Michael Fassbender, Jennifer Lawrence and Nicholas Hoult. New additions to the franchise include Peter Dinklage, Omar Sy, BooBoo Stewart, and Fan Bing Bing. Production has already begun on the film and 20th Century Fox is planning to have Days of Future Past in theaters on July 18th.