Senior Producer on EverQuest II Alan "Brenlo" Crosby brings word that the XP curve in EverQuest II has seen some adjustments. This XP curve adjustments were necessary due to the fact that the level cap is set to be raised from 80 to 90 with the release of the upcoming Sentinel's Fate expansion.
The experience required from levels 1-65 will remain the same but the trek is said to be "smoother," while the speed going from levels 65-75 has been increased, largely due to the fact it apparently took longer to from 65-75 than from 75-80 in the past.
The patch notes can be viewed here.