Cool, this is a good decision
As for renaming playerworlds, here's my opinion:
Graal Classic -> Graal: The Adventure
Graal 2001 -> Graal: <something about bomys>
Graal 2002 -> Graal: Conquest (when it was legal i used to have a 1.28 server by this name, i think the name would fit in with the atmosphere of 2k2)
As for 6 months before releasing Graal 2002... I think it can be ready WAAAAAYYYYYY before that for testing. IMHO, there are only afew more things that need to be done before it can be opened to players.