I still can't build a 2017 on the Canadian, gmcanada.ca web site. Can't get prices either. Couple of weeks ago the dealer couldn't give me a price of the 2017 2500 HDs.
The web site is still pushing the 2016s. And the local newspapers give about $13,000 off the window sticker on a 2017 Duramax. Likely get a few more thousand off a 2016 for a cash deal.
If it is anything like the transition from '05 to '06, there was about a $6,000 difference between the two. '06 did get a six speed, but other than that, they where basically the same truck.
So if you need a new one, is the unknown price increase worth the wait? Maybe not.