thankyou for clearing that up! 8D because id be pretty annoyed if my pagoda and such were deleted XD, so what you are saying is that there will be a portal to a world like the event world for example, and it will connect the two maps?
It's possible that they are doing some sort of rollback, or implementing a more stable build of Bukkit. Or anything else really, there are so many possibilities that it isn't even really worth guessing.