Re: Running out of content?
How does EvE fall into this idea of progression? It works in a very similar way to Perpetuum and is one of the longest running MMO's out there.
They picked up a lot of old players when tech two ships come in but they mainly just recognise that people like shiny stuff so they put new ships in every expansion, even if its just an old one with a new color scheme and a niche role.
This is most definitely something that this game should have done with stealth and ewar bots and should be doing when geocashing comes out too.