Once in a week or a month, you will launch a realm (with custom conditions) and each time, a different event taking place in entire azeroth take place, or just a zone.
One idea is a limited realm. Rates are 100x, and the faction that defeats all enemy faction leaders first will be victorious, and the server shuts down 1 hour after one side wins. This could happen every month.
Or, a launch a realm for a week, where lvl limit is 10 and each faction strives to invade the opposed starting areas. It could be really entertaining and hilarious. You could easily launch realms like these once a month, without really adjusting much data or scripting.
The realm would be online for a specific period of time before shutting down.
Many other similar things could be made like this, let's not be a "no fun allowed" community.
If you're interested any at all, give some feedback!