130mm Rear Disk Hubs
From Pvdwiki
Velocity USA
Velocity USA has a hub that they call the 'road disc'. It's a generic hub and only costs $67.25. I was able to order one with 32 holes. Yeah!
FSA
As of spring 2007, the only way to get a 130mm spaced rear hub with disk is through buying a FSA wheelset. It's really too bad that the hub is not available separately.
Info on the FSA RD-460 Wheelset
In time, we will see more of these hubs. Specifically, they will be targeted toward leisure and cyclocross aplications.
Phil Wood
CDS533 & CDS633, 32 or 36 hole, $459 just hub.
Bontrager
Select Disc Road, 24 hole, $149 for rear wheel.
Easton Velomax
Sagitta Cross Wheel, 28 hole front and rear.