The 2.1 PTR notes have now been released for all to see. However, they are very long, at about 9500 words. For comparison, that's about 40% as long as Kafka's "Metamorphosis" (and almost as depressing, depending on what class you're playing). So I thought it might be helpful to make a condensed version, selecting only the changes that seemed relatively significant.
Note that I left out a ton of changes -- this is only 10% of the patch notes -- in order to make this skimmable. It's still definitely worth checking out the full patch notes if you have a few minutes on your hands. And if you want the short, short version: Epic flight form for Druids, Hunters buffed in damage and pet survivability, Paladins' Illumination cut by half, Rogues get automatic Improved Sap.
Edit: added a few things people pointed out in the comments. Thanks guys!