The initial 3.1 changes are out and the PTR is up.
My 3.1 page has been updated with the latest information.
Survival is getting the largest revamp and is the most confusing at the moment. Looks like the PvE rotation for Survival could get very complicated with the new Black Arrow.
Marksmanship is getting a minor boost through talents and glyphs.
Beast Mastery is getting a minor boost through the pet talent tree (Wild Hunt talent) which seems to be bugged on the PTR at the moment (giving pets way too much attack power).
The most convenient change is the new skill called Stabled Pet, allowing us to use our stables every 30 minutes no matter where we are.
Disengage, the bread and butter PvP skill, is getting nerfed from 25 second cd to 30 second cd.
I think I will continue to think about all these changes and write up a larger summary of each tree in 3.1 in the future.