Well here's my idea.
Say with the new "Ancient Swamp" release coming soon.
Change the level cap to 40.
Have a normal mode allowing you to get to 35 and have the normal drops.
Then have a heroic Ancient Swamp option for 35-40 and better drops.
Why do I say this? Because I got to 30 pretty fast.
30 was when the fun began, but after I got all my loot... I started getting bored.
I'm weird and only enjoy the Archer class so.... I know I could broaden my game
play by creating a new class but I just enjoy Archer so yeah...
Having each expansion to give a 10 higher level cap would bring a bigger challenge.