Subject to change over PTR testing.
Full notes here
My thoughts on the major balance changes.
Barracks build time increased by 5 seconds:
Ah personally I don't think this was needed, I imagine that it is there so bunker rush or two-racks builds are a bit weaker but they weren't really that much of a problem if you paid attention to them.
Hellion Infernal Pre-Igniter damage upgrade decreased from 10 to 5:
This seems reasonable, blue flame hellions while annoying in ZvT were bearable, but this really helps terrans more for TvT. Good change in my opinion.
Raven Seeker missile movement speed increased from 2.5 to 2.953:
Seeker missile previously was a bit of joke, had to be really careless to be hit by it. So good change that should make ravens more interesting. Personally though I think that seeker missile should be able to be launched from further away. Currently you risk your ravens every time you try to use the missile, but then again you can always point defense drone to keep them safe anyway.
Infestor Fungal Growth damage changed from 36 (+30% armored) to 30 (40 vs Armored):
As a zerg player I think this was needed, it might not change things too much, about 6 damage for both regular and armored. Infestor locking things in place is still very deadly though, ZvZ will probably still be Roach/Infestor. Real victim on this change is Destiny.
Overseer Morph cost decreased from 50/100 to 50/50.Contaminate energy cost increased from 75 to 125: Gas reduction is a good send for most zergs, always feels like you never have enough gas. The contaminate change seems unnecessary though. Contaminate isn't really used too much as it is.
Ultralisk Build time decreased from 70 to 55:
I like this a lot, feels like forever for these things to build. Hopefully will encourage more Ultralisk plays, but still think that Ultras need a change in either size or allowing small units to walk under them. They use up so much space right now.
Immortal Attack range increased from 5 to 6:
Good buff, immortals can get stuck behind stalkers a lot. Might encourage more 2 gate robo in PvP.
Warp Prism Shields increased from 40 to 100:
Warp prisms seemed like the easiest thing in the game to destroy, for transports I think this was a needed change. Might make it a bit hard for zerg is you rush for prisms and start warping in zealots in there base before they have anti air though.
Stalker Blink research time increased from 110 to 140.
Unsure if this was needed, will make Protoss FFE into six gate a bit weaker, and make it harder to not to go 4 gate or 2 gate robo in PvP.
Mothership Acceleration increased from 0.3 to 1.375:
Neat, would love to see more mothership usage, following the battercruiser speed buff we did see an increase in them for TvT. So seems like Blizzard is slowly buffing capital ships to get them more useage. Don't know if this will effect the meta game too much at this point. But cooler to see ship battles late game instead of just full gateway armies.
Unit vision up ramps has been reduced by 1:
I like this, having the high ground should give you an advantage. Would like to see more highground around the maps instead of just in your bases, a bit like the middle area in Tal'diram Altar.
Repeated control group and selection commands will no longer count as unique actions for APM calculation purposes:
Good, now maybe people wont feel like they have to spam 400apm at the beginning of a game just for stats, and we can actually see what peoples multitasking ability is in a replay.
Overall I think these changes arent too bad, a few seem unnecessary but I dont play every match up. Will be interesting to see how many of these make it off the test realm or what changes they will have.