Here is what we know so far:
-The movie will reportedly be directed by Deadpool director Tim Miller and is in active development
-Fox is pursuing new projects like this one in case the Disney deal doesn't go through
-It will be the first time Fox has attempted a solo superhero movie with a female main character since 2005's disastrous Elektra
-A solo Kitty Pryde movie has been pitched to Fox twice before; in 2009 by Joss Whedon, who said that Fox wasn't interested at the time; and in 2013 by Juno Director Jason Reitman
-It is unknown who will play Kitty Pryde, though Ellen Page said in 2013 when she heard about the prior pitch for a Kitty Pryde solo movie that she would love to play Kitty again
-Colossus from Deadpool and X-Men: Days of Future Past will reportedly appear in the movie as Kitty's love interest.
-Disney could block the movie from happening if the Disney-Fox merger goes through, but it will take another 12-18 months for that merger to be approved, so enough progress may be made on the movie in the meantime for Disney to allow it to release.
-Tim Miller is currently attached to the 2019 Sonic the Hedgehog movie as an executive producer and to 2019's Terminator 6 as director, so his busy schedule may prevent the movie from making enough progress to ever see the light of day.