2.4.2 What to Expect

Arena Points Calculation
In order to fix problems with players riding the arena win ladder two changes have been made to how players earn points and how teams are matched. If a players personal arena rating is more than 150 below the team rating their will earn points based on their personal rating. Also if the average personal rating of the teams players is more than 150 below their teams rating they will be matched using their average personal rating. This will mean that even if you have two very well geared friends you will still have to fight your way up the ladder.

Cooldown Changes
The cooldowns on many profession spells have been reduced again. A while back Blizzard reduced 24 hour cool downs to 23 hours and 4 day cool downs to 3 days and 23 hours. This has been reduced again by another three hours meaning cooldowns are 20 hours and 3 days 20 hours. A great change this makes crafting that bit more flexible.

Polymorph
Where a players Polymorph spell heals the target as it wanders around as a sheep/pig/turtle. Well the NPC version will cease to do this. I will be interested to see how this changes some approaches to the Aran encounter in Karazhan.

Mount Speed Trinkets
One undocumented change that has been seen on the Public Test Realm relates to speed increase trinkets. Apparently these will now function like enchants for your mount. You will need one such item (eg riding crop) per mount. It is slightly cloudy as to how this effect Warlocks and Druids who have a mount created by a spell.

Sounds
Many sound errors have also been fixed. Hopefully this means I wont be able to hear that priest shielding from the next zone.

Mail Boxes
I use the mail box as my bank, mailing all the junk i want to sell to an alt. It has annoyed me no end that when they made all those great changes to tracking that they didn't allow you to track mailboxes. My wish has been granted, I will not be able to track the pesky buggers!

The official Patch Notes can be found here.