can not use ad_rewire and in my search in the forums I found reference to the "MSPReWireDevice.bundle" which does not exist any where in the Max 6 folder.
I opened the installer (Max 6.0.7) and checked inside, the bundle is not there. however it exists in Max 5 installer.
some other user reported recently that placing a copy of the "MSPReWireDevice.bundle" from Max 5 to Max 6 , enabled the ad_rewire menus and he could select inputs in Ableton Live but he also reported noise. so it worked to connect the applications but failed to deliver audio signal.