I haven't been on the 3.1 PTR at all. I haven't felt motivated this time, since the changes aren't as big as the 3.0 PTR (we're not getting two new tiers of talents, and whatnot).
The changes that have been put forth for hunters, though - not the ammo changes, or the pet changes, but the tweaks to the Marksman talents - they're going to require some spec and rotation tweaking.
Why? Daze, Chimera, and Steady Shot.
I'm using a Chimera, Aimed, Arcane, Steady x3 or x4 rotation. I'm looking at this spec. So I'm going to want to switch things up - probably Arcane, Aimed, Chimera, and then my Steady Shots, however many I can squeeze in with Haste. (Three or four.)
This hinges on the changes to Concussive Barrage - Chimera and Multi will have 100% daze chances. PVP change? Oh, no. This is to buff MM hunter's Steady Shot damage in PVE. (Okay, maybe not, but it's how I'm going to use it.) Add onto that the bleed from Piercing Shots which Aimed, Chimera, and Steady will add...
Yeah, bosses are immune to the daze. This rolls Concussive Shot's effect into Chimera and Multi, though - which means you have a multi-target daze. For non-boss situations, this is going to up Steady Shot damage, as well as give a hunter more kiting options.
Oh, right. Who still kites nowadays?