Is airplay via iTunes the only way to get Multiple Air's to play throughout the house in sync?

Is there a way to get multiple Air's to play web radio or share songs on usb/or NAS and play in sync?

Wasn't there going to be an option to have the ability to put two Air's in one room, and designate one as left, and one as right effectively giving one one large wireless stereo? or did that get dropped?

2xAA
M80/VP150/VP160/QS8
4xM3/M22OW/M2OW/VP150OW/4xM3IC/4xM3OW
EP500/800/HSU VTF3/SVS PB2k/SB2k/SB-12