New 3.1 changes

Source - WoW Insider

Ammunition: All types of gun and bow ammunition now stack to 1000. All quivers and ammo pouches no longer provide haste. 15% ranged haste is now built in to Hunter Autoshot.
If my internet wasn't capped you can bet I'll be on the PTR testing that right now... *sigh*

Call Stabled Pet: This new ability lets the hunter remotely access the stable. 30 min cooldown.
Yes, we already knew that. But according to BRK, it has the potential to delete your pets. Use with caution!

Explosive Shot: Base damage lowered by 10%. Attack power scaling reduced by 12.5%.
Flat out nerf to Explosive Shot if I ever saw one. :(

Quite a long list of pet changes too!

Thunderstomp is no longer a gorilla-specific family ability and is now available to all Tenacity pets. It has been reduced to one rank.
I LIKE THIS. Pardon the caps. I've never been a huge fan of the gorilla as a pet, the only reason I got it was because it was the best tanking pet. But now that they've made the best pet tanking ability baseline, I can just go get a bear or something. Yay!

Furious Howl (wolf special ability) now stacks with Battle Shout and Blessing of Might, however, it only affects the wolf and hunter. Its effect and cooldown have been doubled so that it provides the same benefit but isn't up 100% of the time.
Very interesting. I've been tossing up for a long time over getting a wolf, since I have a spare stable slot. But since Furious Howl doesn't stack with Might or Battle Shout, I never did. Looks like I'll be heading to Storm Peaks for one soon. It'll be interesting to test dps between wolf and cat if you're Surv or MM.

New Talent: Wild Hunt: This new two-rank talent is available to all 3 pet trees. It increases the stamina and attack power inherited from the hunter.
Cunning, Ferocity and Tenacity pets now all have +5% damage, +5% armor and +5% health bonuses.
Hooray for Blizz trying to make pets more survivable in PVP! Not that I do much of it. But yay!

They've also added new last tier talents for pet talent trees, which look very promising.

A few nice glyph changes too...

• Glyph of Explosive Shot: Increases the critical strike chance of Explosive Shot by 4%.
• Glyph of Explosive Trap: The periodic damage from your Explosive Trap can now be critical strikes.
• Glyph of Kill Shot: Reduces the cooldown of Kill Shot by 6 sec.

What do you mean I have to choose between my glyphs now?! What is this?!