| Why not allow people to start at the the level where they can group with people at the previous cap when you introduce a new expansion? Edit: For example 52 (I think) in WoW when TBC came out.
You could do a neat series of scripted events/quests. Say you start as the character and you have to complete the events with the help of a few friends. The length and difficulty of the events could be tuned as needed to keep them challenging but fun. Once you complete the events you are given a set of crappy gear and let loose in the world. The events should be tailored on a class level and designed to teach you the core set of skills you will need in groups.
You could provide a similar mechanism to allow people to promote an alt.
Sure you end up skipping content but it keeps a bulk of your players in a situation where they can find groups and enjoy the multiplayer aspects of the game. Old world zones usually end up as tourist/twink locations anyway and the value in that is minimal at best. | 