May I suggest a world format that has not been done in a very long time?
A 5,000 slot (Firestorm) world with Forgotten Attacks and morale. This world setup has in fact been requested by many players that have had a negative view of the current WCS world setup. It would be nice to run a world to determine if indeed these type of worlds can attract and keep players. Of course, around 98 percent of all activity for the first few months will be farming so perhaps plan for, set-up, and publish a schedule of "infected events" that will break up the monotony of normal farming.
I think the inclusion of guaranteed events will keep players motivated in morale-type worlds.