Some of my wishes for this game,
If possible, make sure all zones are valuable and relevant to all levels of players so that we don't have empty zones few years after release. In them park games like Eq2 and WoW, you only have activities in higher and newer zone only. All other are zones are dead and empty. This breaks immersion and in turn "cheapen" the overall world.
After 5 or 10 years of release, the power gap between veteran and new player is huge in games like EQ2 and WoW. In order to bridge the gap, these games add "catch" up mechanics like increase experience in old zones, nerf mobs etc. Again these mechanics "cheapen" the overall world. I am not sure what is the best solution here is but I think there shouldn't be *huge* power gap between new player and a veteran 10 years after release. However veteran player should have far more options than a new player 10 years after release. These option could be anything, for example a new player only has access to 10 skills but a 10 years veteran has access to 100 skill to choose from etc.
Hope I made some sense