I have just come back from PAX, where blizzard had a large booth in the expo hall. Karune and a good number of other Blizzard employees were there and playing people, giving out beta keys to anyone who beat them.
I talked to Karune about the 1-hatch queen imbalance that TL had apparently found, and he was utterly unconvinced that it is the game winner it claims to be. He did acknowledge to the fact that it is a very powerful build, but that somebody who knows the game past trying to play like you do in BW can counter it without too much problem. He then went into a few details on the counter for toss.
basic BO for protoss counter, though I don't know the new supply timings they are fairly intuitive and doesn't include cutting probes.
Pylon at choke + scout, seeing 10-pool
2x GW at choke making a soft wall-in 1 zealot wide (this is easy with the new way buildings block paths)
on most current maps 6lings from 10 pool get there just after the 1st zealot spawns, and just as the 2nd GW finishes.
The zealot is in a gap 1-2 zerglings wide, meaning heavy losses, if you attempt to kill the zealot you may get in with 2-3 lings before the next 2 zealots pop out, but with the new zealots + worker micro, the choke remains solid while the 2-3 lings are dispatched
This comes down to that the toss has a choke to defend with zealots against lings, and this works very much the same way it does in BW, very badly for the zerg
At this point the zerg is facing both the threat of a 2-gate rush and an essentially unbreakable choke for lings
The protoss gets their obelisk and both gas right after the 2-gates push off the attack and they see if the zerg is continuing to press with lings (in which case keep a healthy number of zealots pumping) or swapping to hydras.
Going to hydra tech, still off 1-base, as trying to get an expansion means the protoss can overrun you with his 2-gate (queen cannot prevent scouts that are not on the creep, meaning your natural is scout-able)
As the protoss staying 1-base, whatever build it could be, from lair teching to mass hydra, the toss just needs to tech up slightly to stalkers warp gates and disruptors.
Now comes where the toss has to weather out the mass hydras until zealot charge finishes, which is done by a combination of stalkers on the ledge (all current maps provide a ramp for your main) and well placed force fields from the disruptors. The goal here is to micro back any stalkers on the ledge with low shields, preventing the hydras from getting free pot shots at the buildings from the low-ground (using overlord for the vision) as well as blocking off the ramp if 5-6 hydras get to the top, cutting off their escape and trapping them in range of the stalker force behind the gates.
What we/Karune found was that the toss is able to hold the choke without spamming just stalkers, allowing for a large combined group of zealots with charge and some stalker backup to cut through any amount of hydras you can get off 1-hatch.
At this point in the game it devolves into either a quick protoss steamroll, or a drawn out fight where it goes back and forth in the middle, essentially a fair game.
Karune, being primarily a Protoss player was unable to comment on specifics about the terran counter, but mentioned that it is the overpowering strat in ZvZ currently, and they are looking at ways to freshen up that match-up.
From what I observed of I believe Cydra playing terran, his off-race, he was able to hold his ramp by double supply depot + barracks wall-in, lifting the barracks and building a bunker in the spot the moment a chance appears. We didn't see him truly tested against a polished 6-ling into hydra build though, which was unfortunate.
In the games played, both against other blizzard employees and attendees 1-hatch queen's initial fury caught a number a bit off-guard, but soon defensive builds combined with timing attacks early mid-game were at the very least on balance with the people doing 1-hatch queen. I won't try and pretend we were experts at the game, so it may be that we are doing something with 1-hatch different then you guys were, but Karune's challenge to anyone trying it against him stood up, and he remained undefeated through all his games.
Additional notes, this may be completely wrong, it's just some observations I made after a successful muta harass.
In the one longer game I played against a Terran Cydra, I found how I believe muta harass will work now. In BW you're very able to micro well enough to kill off marines from the terran ball. This doesn't seem to be very true anymore. The change that makes muta harass still very viable though, is the removal of the medic. Since there is no Medic unit until starport, he will not have any significant numbers of them by the time you have your muta harass in full swing, in addition, they are slow and vulnerable.
In BW the reason the terran always had his marines in generally the correct area without having to split up was due to being able to stim, relying on medics to heal up that bit of damage. With no medics there, if the terran is not stimming his marines, you are able to dance around his base with your mutas picking off all sorts of things, simply moving when the marine ball arrives. If he is stimming, wait until they are all low hp, and then begin your harass on the marines. when you can split your shots and kill 5-10 marines/muta volley it's already over. If he has some medivacs around, generally I found they lagged behind the marine force and had slow healing (simply because of the reduced numbers compared to BW medics)
edit: couple spelling errors etc.