This made the news yesterday:
Construction begins next year.
In Anaheim, Disneyland will be removing the Big Thunder Ranch and some backstage areas to get that 14 acres of Star Wars land, making this the fourth current land off of the hub and fifth ever (New Orleans Square, Critter Country, and Toon Town are the others, the underwhelming Holidayland that was taken out in the '50s was the first one ever off the hub). Based on what I'm seeing, it looks like the Disneyland Railway will either have to be moved or run through the land (or run through a tunnel separating it from the land) as it currently runs right through that space.
I was at the D23 Expo presentation announcing the details of the land, the land is going to be an all-new planet designed specifically for the parks, it'll have 2 major attractions including a Millennium Falcon attraction, and all the shops and restaurants will be in the land's "story". Here, you can be the guy right behind me with the camera and watch the whole announcement: https://www.youtube.com/watch?v=tWoFSbft3OU
In the meantime, both parks will be getting Season of the Force overlays based on what they've learned from Star Wars Weekends in Florida, special events, SW Launch Bay, an overlay on Space Mountain, and Star Wars fireworks.