Figured that Apple would have released a host of dongles in the store today only to find one... The USB-C to Thunderbolt 2 adapter and no USB-C to Gigabit Adapter.
That means the only way to Netboot a new Macbook pro is to use the following
Apple USB-C to USB-A adapter
to
Apple USB-A to 100mb Ethernet adapter.
Cost $50
Or
USB-C to ThunderBolt 2
to
Thunderbolt 2 to Gig Ethernet.
Cost $80
Yes the store shows a Belkin USB-C to Ethernet Adapter but that does not have the built in firmware to netboot like the Apple ethernet dongles do.
I guess the writing was on the wall with the 12" Macbook.

