Notch has just announced on his blog that the Nether will be playable on multiplayer on Minecraft beta 1.6.
Notch posted on his personal blog The Word of Notch that one of the main features is Minecraft beta 1.6 will be “a functioning Nether in multiplayer.” He went on to say that “Nether. In smp. Fun!”
Minecraft beta 1.6 will also bring in Maps and bug fixes and so far only has a release date of “not soon”.Minecraft Beta 1.6 Brings The Nether To Multiplayer,