My sense from Sev's perspective on the Cordo show was that they wanted to modify Hardcore so that it happened on typical servers. The Latern/Mists being their first attempt here. For some folks, like me, hardcore was an event that I skipped and b/c it drained the server population it meant I took a break during Hardcore. (Not complaining, as I need some afk time)
You may consider forming your proposal around the idea that the event happens on primary servers...possibly the mega servers which will be 64-bit. For it to be a success I think you'd need to give folks the option to post LFMs that only event folks could join (but make it optional). Possibly give characters participating in the event a special aura so that event folks are able to identify each other. Also, you could make each quest have a new mode, similar to what reaper is, but during event you'd have the extra selection to be able to enter the dungeon as an event. You'd also want the leader board to be updated across mega-servers.
The Lantern event is odd b/c they want it to encourage folks to test out their server, so I doubt it's the template going forward.