The server has now been updated to Minecraft 1.6.6!
Among the other plethora of updates that 1.6 brings, please do note that as with all updates some things may break. That aside, the Nether can now be accessed via spawn:
Maps are currently not working (I assume this is a Bukkit problem?), teleporting to players is broken, creepers cause explosions again (but are logged for rollbacks) and iConomy is still waiting for an update.
Please notify us of any other issues and bear with us as we transition!