Update - The patch notes have been updated once again with the resilience changes and more class changes. New additions have been marked in the notes below!

World of Warcraft PTR Patch 4.1 - Updated February 28th
Originally Posted by Blizzard(Source)x - Notes added in the 2nd notes update of the day.
GeneralFlying mounts can now be used in Ghostlands.x Resilience scaling has been modified for linear returns, as opposed to increasing returns. Under the new formula, going from 30 resilience to 40 resilience gives players the same increase to survivability as going from 0 to 10. Resilience now scales in the same way armor and magic resistances do. A player with 32.5% damage reduction from resilience in 4.0.6 should see their damage reduction unchanged in 4.1. Those with less than 32.5% will gain slightly. Those with more will lose some damage reduction, increasingly so as their resilience climbs.
Classes