So everyone is entering headphone market like a bunch of zombies jumping into an alive human (as I wrote on other thread, I may be able to hear that amp as well.)
If McIntosh® is entering the headphone arena, they'll almost certainly have at least one model compatible with portable devices - the LD/HP transducer family is legendary in home audio. I'd like to read how the first LD/HP headphones fare against existing summit-fi dynamics from AKG®/Harman, Sennheiser® and beyerdynamic®, in addition to both pre-existing planar-magnetic models, the Oppo® PM-1 (assuming production models are available for review), and the benchmark-holding STAX® SR-009 Earspeaker™ electrostats.
My mistake folks. I misread Scott's post. It's a headphone amp, not headphones. My sincere apologies.
Edit: Looks like McIntosh does have a pair of headphones in the works, MHP1000, please go to the appropriate thread for further discussion :-