With the most recent patch released on the PTRs, the following changes have been made to Naxxramas.

Plague Wing
# Players should no longer be able to fall from the balcony in the plague wing.
# Heigan the Uncleans entry door will not open until Noth the Plaguebringer has been killed.
# The Plague wing entry room will now completely respawn when a group wipes.

Spider Wing
# Anubrekhan: Fixed Frozen Rune positions in Anub'Rekhan's room. They were previously unselectable / unusuable.
# Anubrekhan: Fixed Locust Swarm and Impale animations.
# Spell effects will appear more aligned on several mobs.

Abomination Wing
# Patchwerk: The door beyond Patchwerk will now only open if he is killed.
# Patchwerk: Aggro shouts have been slowed down so he doesnt spam introductions in chat and audio.
# Patchwerk: He will no longer travel outside of a given range.
# Thaddius: Zone-wide shouts will no longer have audio vocals.
# Embalming slimes are now on a three minute respawn timer.
# Sewage slimes are now on a three minute respawn timer.
# Patchwork Golem no longer looses aggro on war stomp.
# Mad Scientists: Fixed problems with portraits and textures.

Deathknight Wing
# The endless slime pits in the Deathknight wing now have proper collision and slime.
# Deathknight Understudies have been changed from level 61 to 60 and their Shadow Resistance set to 0. This should make the regular periodic resists happen less often.
# Deathknight Understudies now lose aggro after casting Mind Exhaustion.
# Shades of Naxxramas no longer infinitely spawn a portal.
# Living poison slimes before Patchwerk have been spaced out a little more to give players a little more room to try and avoid them.

General
# Mr. Bigglesworth will no longer respawn. R.I.P. =(
# The "Echoes of War" quest requirements were changed from requiring the Heart of Anub'Rekhan and the Head of Instructor Razuvious to 8 Deathknight Captains and 3 Venom Stalkers.
# Various creatures now move faster.
# Stealth detection has been applied to most creatures in the zone.
# All Non-Boss creatures in the zone now has a leash distance.
# Added vendor Jimmy McWeaksauce to the center of Naxxramas. Jimmy sells the following items and is generally a cool guy:

* Free Repairs
* Free Res sickness removal
* Spell reagents
* Tome of Tranquilizing shot
* Rogue poisons

Some players have reported a pin pad popping up on the login screen of their PTR client.

This is a security feature which is currently being tested, but it’s not relevant for Europe at this time.

# Key rings have been added to the game.

* Level 1-39 = 4 slots
* Level 40-49 = 8 slots
* Level 50-60 = 12 slots

O co im chodzi?

We're pleased to announce that the keyring functionality has been completed and will be in place for patch 1.11. When a player first acquires a key, they will automatically acquire a keyring that will hold permanent dungeon keys. The size of this keyring will increase as the player goes up in level -- as seen below.

14:40 CEST:
It has been decided to shut down the European PTRs until this evening. We expect to be able to update you around 20:00 CEST this evening.

yes yes yes! Udalo mi sie skopiowac chara na PTR:P

jest absolutnie ciągle down więc wiesz... nie to co ptr us on działa od niedzieli a nasz ptr tak jakoś tandetnie.

Prosta sprawa, HQ jest w US, maja test servery lokalnie, wszystko sobie tam testuja. Test servery w EU sa tylko po to zeby ludziom mordy zamknac i moze ktos opisze jakiegos buga ktorego i tak w us znajda..

Nie rozumiem calej tej paniki naokolo PTR, i tak za 2 tygodnie to bedzie live, po co sie pchac i marnowac swoj czas?

a ty jak zwykle ;P