The latest patch notes for Guild Wars 2 have been posted on the official site. Chief among the long list of changes are alterations to several dungeons as well as the closing of exploits some players had been taking advantage of in recent weeks.
We’ve made some significant updates to dungeon rewards. I wanted to try and clarify them here. All of these changes have been the result of an original exploit which was letting players receive upwards of 20 levels by completing a single dungeon run. We initially closed this exploit, which caused some new problems. The result is this new system which should increase dungeon rewards for players who play though them normally but help curb inflation of rewards for those who are using exploitative methods to farm them.
Read more on the Guild Wars 2 site.