hi,
based on what I saw with different servers when comes time to merge them and reading here in the forum that it is common thing, I came up with an idea> melting 2 ideas, Diablo dificulty level idea with multi server system>
so bassically, there would be different servers with piramidal hierarchy, when we start the game we start in normal dificulty, once we get to 60, and done lets say some very important quests, it opens a gate to an other dimension with much more dificulty and new story but in the same world.
once there we will find that everything is different, it is the same game world, but the cities are different in a different location, with new story which complete the previous. The loot is better than in the previous, and we will have to start once again to get more 60 levels and complete all the story to get the next gate.
the end world will be fully pvp