I have always said that this would be a great extension for the Ethan Allen Express. It would put downtown Middlebury, Shelbourne, and most importantly Burlington online with Amtrak. I would think that such a train would carry a lot of college studens - I would presume - as well as the typical tourist to the areas. When I take the train to Vermont, I typically take the Adirondack northbound to Port Kent (and ferry over from there to downtown Burlington) or rent a car out of Plattsburgh, NY to get to Burlington, VT. This train option gets me to Burlington, VT faster than the Vermonter! Then southbound, I typically take the meandering Vermonter back home to the NYC metro area.
If Vermont DMUs the Vermonter route - hopefully offering a double frequency in doing so (and discharge/receive only beween New Haven and Springfield to protect Vermont's interest), the Ethan Allen extension to Burlington may be a nice trade off. Course, then we'll see if the DMU project gets extended to the Ethan Allen Express. I just hope in the DMU plan that comfortable seating, nice wrap-a-round windows and food service is offered. One would think DMU service would work best for short routes, rather than the longer Vermonter route. And the one-seat ride issue is going to be interesting to deal with!
I would hope Amtrak could get Vermont to extend the Ethan Allen Express to Burlington (if that's the intention) quicker than the timetable menioned above. A lot of infrastructure for stations is still in place from when the commuter train operated from Vergennes to Burlington and then the Green Mountain RR excursion operations.