JDH: I like the idea of allowing other people to host servers and we let the players decide which servers they want to play on. I'd like to make our game massively scalable - and to do that it strikes me that we'd want to let enthusiasts share some of the processing cost (i.e. serving their own versions of the game). These other server networks would all be linked together to produce in essence one game.
We'd need to have some way of identifying the owner of the server network so that players could decide who to trust - we could employ a trust certificate type scheme (a la plug-in downloads) but we probably wouldn't need that as swapping between server networks would most likely only be an exceptional and explicit action from the player.
On top of these seperate server systems (galaxies?) there would be an owner uber-server (owned by us) that would manage transitions between galaxies - this server could control mapping between markedly different galaxy models. This approach might help us make the SpookySpace(TM) ;-) massively scalable (which of course will help us with our hidden agenda of world domination).
Furthermore, to stack the commercial deck in our favor we could make it more attractive to start in one of our own galaxies and make it so that the player has to achieve the ability to jump to another galaxy. We'd make it real easy for them to "fall back" into our galaxy.
So, for example:
We start off with modelling a single galaxy and when we've got that down we introduce a galactic drive capable of catapulting you through to an alternative galaxy. The galactic drive technology works in such a way as to allow you to easily return to galaxies already visited. Galactic drives are hard to come by (very expensive and scarcely available - so you have to be rich and you have to track them down). While players are lining up and playing our first galaxy to death we're busy working on a new galaxy and we're incorporating all the nifty ideas that we've discovered since writing our first galaxy. From this the second galaxy is born - we decide how to map the attributes of the first galaxy to the second and start the second server network and slowly players progress to this second galaxy. IOf course our success is phenomenal and people want to host their own galaxies - we give 'em the specs and they code their own galaxies from scratch or we sell them the first galaxy source code. Once they've completed their model they ask us to be included in our uber server and we work with them to agree a mapping between their galaxy and the galaxies to which they want to connect. Slowly our whole universe grows ...