Ed,
ES44DC versions are still on track for March delivery, though one would expect we may split it like we did the AC's as we just can't test that many that quick. If you check our web page for 'Upcoming Releases' you can find the latest schedule for announced items.
All of the sound equipped GEVO's utilize SoundTraxx Tsunami decoder, just modified to fit into our locomotive footprint. The non-sound have the SoundTraxx motor decoder, thus it is DCC out of the box.
Thanks
-richard