Hail, druids. There really aren't too many known changes to our class on the patch 3.3 PTR. As I write this, the only gameplay change you're likely to notice will be the buff/nerf to pet avoidance, which will only affect the Balance talent Force of Nature. More experienced Balance players will have to chime in here, because the wording on the change makes it sound like they're referencing an existing feature. I'm racking my brain trying to remember if Blizzard's ever done anything to tinker with the treants' survivability versus AoE damage, and I don't think they have. My guess is that the wording is just in line with similar changes in other classes with access to pets. Anyway, the change reads as follows:
Avoidance (passive): Now reduces the damage your pets take from area-of-effect damage by 90%, but no longer applies to area-of-effect damage caused by other players.
Apart from that, the only other known change to the class is a bug fix on rank 15 Rejuvenation (correcting the base duration from 15 seconds to 12 seconds), but we'll keep an eye on the PTR for you, and any additional changes will be noted here.