About all I could find out is that it should be released with the rest of the 2017 Models and it appears it has borrowed a 450 motor from Yamaha's off-road bike and uses the drive from another company who specializes in that type of drive, No price yet but up here in the great white north (northern Michigan) I think it would be the answer a lot of us have been looking for.
It appears from people who were at the unveiling that the bike is a Sherco 450. I'm not very familiar with sherco but it looks pretty rare in the U.S. and started out as a trials bike company. Arctic cat has done a deal with Yamaha for engines, but maybe that's just for the multi-cylinder engines. For some reason they decided to move from Suzuki to Yamaha. Polaris bought Timberline (tracks). Who knows what the winter of "17" may bring.
Of course, even that is open to change. There has been very little promotion to the public and the one time it was displayed, it was only for a minute or two then it was covered up. We'll see, probably in September, and there's a good chance that Polaris has something in the works as well.
If you look closely at the frame, it matches the Sherco frame. I talked to my dealer and he heard they would produce just a few to see how it goes. I think the Sherco brand is pretty expensive so it may not be cost effective for most snow people unless they have a lot of cash.