Panasonic just released pricing for the 4K video shooting Lumix GH4. It will cost $US1700, and it's available for pre-order through B&H now.
The price is extremely reasonable, considering many had expected the camera to show up over $US2000. There is a bit of a catch though. The interface unit that will provide professional connections for recording the best quality video will cost a staggering $US2000, more than the camera itself! For a bit of a discount, pick them up as a package for $US3300.
It was pretty much expected that the interface unit would be for professional production environments, so the high price won't bother most. If you are just looking for bare-bones 4K that is highly compressed, and a pretty darn good micro-four-thirds still camera, $US1700 for the GH4 is pretty decent. It should be shipping at the end of April. Australian pricing and availability is yet to be announced.