With the recently announced merging of the Bukkit server project into the official Mojang team we are presented with an uncertain path forward.
As Minecraft has always been a fluid and ever changing entity I always knew that nothing about the server world would be permanent. some change would eventually come along that would necessitate starting (at least somewhat) from scratch.
Within the next few days I will attempt to update to 1.2. Hopefully nothing major will break, but most likely something will. I'll try and keep current functionality working, but there are no guarantees. Anything that can't be fixed will be discarded.
I will then begin exploring what it would take to start the server fresh. This would most likely include a new world map. I will however try and maintain a certain number of buildings from the current worlds within a newly created combined world. This world would likely contain the core of survival world and Endor imposed into a freshly generated 1.2 world.
The amount of time and effort needed to do this might be more than I am able to provide in a short time frame. We're talking probably at least 1 month. Possibly less if I am willing/able to sacrifice certain current functionality.
I'm also reluctant to make a considerable effort in redoing things if it becomes apparent that Bukkit will be largely abandoned until the new combined mojang/bukkit modding api is unleashed. Mojang has promised to make the transition painless, but there are no guarantees and the amount of work they need to do is enormous.
With all that said I will at least promise you one thing: a fully functioning 1.2 compliant server within the month of March.