Oh yes yes, indeed this is an idea floating around lately. The idea (And right now it is only an idea and nothing solid) we are planing on making Zombie Apocalypse for SMP, but not just any server. To start, it will only be exclusive to our server and no other until we finally see fit to release it for download for others to use. This is all very hush hush though, and now I have to kill you for knowing.