Unlike Smash, we're actually getting official patch notes for this game, though unfortunately most translations I've seen so far are crappy, so here I'm just gonna try to make sense of it, namely the nerf'ed part. If anything is incorrect simply let me know! Here's where they were initially posted: http://www.nintendo.co.jp/wiiu/agmj/update/index.html

Splatfest

– If it takes too long to find another team, you can fight the same team again. 

* Even if playing against the same team, Splatfest Points can still be earned. 

* Only the opposing team’s results will be counted at the conclusion of a Splatfest battle.

– If you begin the software before the Splatfest start time, an adjustment will be made where you may be able to begin 5 minutes before the start time (from the start time, you can participate in all areas). 

* The purpose of this is to reduce congestion that would occur immediately following the start. 

– The number of Super Sea Snail increases when you acquire the “Charisma” and “Eternity” titles when the team that voted loses.

Special Weapons

Kraken - Now works like the Bubbler, where shooting it pushes it back.

Inkstrike - More consistent in terms of how much ground it covers.

Gear Abilitys

Ink Res - Less effective.

Ninja Squid - Heavier Swim Speed reduction

Stealth Jump - Further increased Super Jump time.

Other

– Various game content has been fixed to better customer experience.

A lot of this came from gonintendo, specifically here: http://gonintendo.com/stories/237121-splatoon-version-1-3-0-update-hits-japan-on-july-1st

However their special/ability section isn't as accurate, since they obviously wouldn't buff the most overused ability in the game. As for my personal thoughts, it all seems good to me. Not entirely sure what the Inkstrike adjustment means exactly, but no doubt the Kraken was OP, and those abilitys were over-centralizing things with almost everyone using them, yep even me! It's also great to know that our Splatfest will run smoothly, but I'm still hoping they improve matchmaking in general.

"Unlike Smash, we're actually getting official patch notes for this game"

I... I don't even.

I blame Sakurai.

Inkstrike being more consistent for better or for worse...? :/

Ninja squid patch is the worst for me though D:

I'm glad the Kraken is nerfed, it was the most overpowered special ability.

They ruined the inkstrike special:(

I hope they've fixed the matchmaking for the normal battles too, would be nice if you played against regional players.
Been doing a couple of random rounds always with japanese players, and sure they could be ninjas but not ghosts, the laaaag.

Now to find new shoes for to sub my ink resistance ones.

all of them are overpowered if you know how to use them

I barely ever lag tbh, but yeah regional matchmaking should be an option like in MK8. But I can understand why they didn't do it, because they were unsure about how it would sell and to split your community would be terrible if sales weren't good.

Nah, I mainly use inkstrike and the downside is that you have to take your eyes of the tv and stand idle for a time. That was its weakness. The Kraken had no weaknesses at all. You were invulnerable, had increased speed, could still paint the ground with your ink and could easily kill many enemies.

Glad to see the Kraken is getting a nerf, that thing is way too good.