I would certainly hope it would be less than the 5D3 was at launch.
The 7D2 is a more capable camera with more bells and whistles and more advanced AF, (Vs. 5D3) and it launched at nearly $2K less than the 5D3 launched. <<<--- (OK, I admit, that's some heavy rounding!)
You can not tell me that a full frame sensor costs near $2K more than APS-c. (6D proves this)
It just seems to me that with the 7D2's price point now established, Canon HAS to be more realistic in the pricing of the 5D4.
At the same time, I also understand that the 5D3 is already a very good competitor with the 7D2 for what it does. 5D4 is newer, FF etc,. IMHO around or just under $3K would seem more reasonable.
On a personal level, If it's $1K more than 7D2 (approx $2,700.00) I may be able to jump right in. If it's over $3k, I won't be part of the launch party