I just got a peek at the ‘08 catalog from Syncros, (which you can download from their site) and I saw a rim that will be introduced at Interbike called the DS28. Here are the salient features of this disc only rim.
-True Track Technology, which indicates this model has a sleeved joint for better rim strength.
-Bead Lock System, which helps prevent tire rotation on the rim at low pressures
-Concentrically drilled spoke holes for a truer rim wheel build.
-Available in matte white or black
-26″er model weighs 545grams, so the 29″er rim should be at least 10% heavier.

There is a rumor that a pre-built wheelset will also debut at Interbike as well. Twenty Nine Inches will be on the look out for these products there.