My suggestion(s):
General: We only build and think about 1 big custom land/place - Where you can lvl from 1-80 just like the normal wow, but a whole new place, with custom quests, items & mobs + Fun things like Boss events, stair events, (saw) events and so on..
Total=
1 Custom Class
1 New Place/Land
A lot custom Quests, Items & Mobs
Events
PvP Arena
1 New Custom Main city (Pve)
Rare mobs, with good custom drops.
Custom Dungeons/Raids.
Bosses around the world in Caves and so on.''
That would be awesome :-)