Although I don’t necessarily disagree with this change from a designer/balance standpoint, I know all my leveling toons under 60 will be very disappointed. Oddly, this hotfix is not included on the list of hotfixes that blizzard links at the bottom of their post, as of now anyway. The original text can be found HERE.
We are applying a hotfix today to all level 1-60 dungeon quests for Kalimdor and Eastern Kingdoms dungeons which will significantly reduce the amount of experience they award.
While dungeons should remain integral to our evolving storylines, and great places to collect gear in cooperative environments, we need to make sure each player’s questing progress remains relevant as dungeon quests are completed. In many cases we’re seeing players enter dungeons to complete quests, only to come out ahead of the leveling curve for the zones they’re in.
This change should allow players the opportunity to reap the benefits of running dungeons, while not outpacing the leveling flow from levels 1-60. At this time there are no plans for making any adjustments to dungeon quest experience for Outland, Northrend, and level 80+ Cataclysm dungeons.
You can find a list of all of the latest hotfixes here: http://us.battle.net/wow/en/blog/1232869