Corrupted gear
Corrupted drops now scale every stat on the item by 5% per corruption level, not just Health, Strength, Intellect and Item Power. The altar preview shows the total bonus.
Corrupted and Heroic weapons: weapon damage now scales with corruption level and the Heroic World Tier bonus, matching the item's other stats. Tooltips show the scaled damage.
Adventurers
Recruited adventurers no longer leave after an hour. They stay in your group until you kick them.
Downed adventurers can now be targeted and kicked from the party frame. Trading with a downed adventurer is disabled.
Talent points
Characters levelled under the old 2-per-level rule are topped up to the current 3-per-level total on login. No points are ever removed.
Druid
Quickening now works when cast on yourself, including with no target or an enemy targeted. It correctly consumes Renewal from whoever it heals.
Abilities
Any ability whose requirements check the target now evaluates the actual cast target, so self-casts and smart-casts behave correctly.