I have a RRS HSE on order since July (took an existing build slot) for delivery in September. I've spoken to the dealer this morning and he was saying that orders are all over the place at the moment due to model year changes, with my car's delivery date changing both forwards and backwards at the moment...
He was saying that there is some possibility that I may end up with a MY17 car, but he's not sure.

Has anyone else heard anything about MY17 cars and delivery dates?

I had a 16.5 on order it was on the production line the last week in September and handover mid October.

I have cancelled this car and am waiting on a MY17 build slot as people on here have said they have delivery in December on the MY17 and my dealer suggests December / January for delivery of mine. I am yet to get confirmation of the details though.

From what I understand though if you have a build slot already the car will not change to a MY17 as Land Rover would have the parts ordered to your car way in advance of it going into production and I don't think they would run out of stock and start switching orders but I'm happy to be corrected if it happens.

That's pretty much what I thought, and I don't personally actually mind getting either a 16.5 or 17 car, but I will wait and see what happens...