Both B&H Photo and Amazon are preselling the Panasonic GH4. The body is priced at $1,698.00 on both sites. B&H expects the availability to be “end of April” while Amazon has flat out announced that it will available April 30th.
The optional interface unit that attached to the bottom of the camera known as the Panasonic LUMIX YAGH Interface Unit is priced at $2,000. The unit is optional, and it is intended for professionals who need time code and other odd features, and will like not sell very well (at least at the obscene price of $2,000).
The big deal about the GH4 is that it is a mirrorless camera (kinda like a DSLR without a mirror inside) that can shoot 4K video for under $2,000. The GH3 was considered one of the most powerful video cameras under $3,000 (many people would still take a GH3 over a Canon 5D mkIII). So what do we expect from the GH4? Basically it is set to be the ultimate video camera under $2,000. Yes, the $1,698 price tag may be daunting but you are getting a professional video quality from a highly regarded pedigree (the GH1, GH2, and GH3 all received massive acclaim from the film community).
So, is it worth it? If you have a 4K TV, a 4K computer monitor, and the computer resources to edit 4K video then I think this camera is defiantly worth it. You are buying a camera that will not feel obsolete for at least half a decade. If you don’t have a 4K TV or a powerful computer, you may want to invest in a TV and computer before you invest in a GH4.