In addition to the FDR-AX1 - their just announced $4,499.99 "consumer" camcorder - it seems that Sony has another version, the PXW-Z100, that offers a few more features and looks almost identical to the FDR-AX1. The PXW-Z100 offers: XAVC Intra 422 recording (the same codec found in the PMW-F5), 3G-SDI (for HD output), variable frame rate for HD and a Wi-Fi Remote.
The significant difference is the recording format and the support for 4:2:2 (the FDR-AX1 uses 4:2:0 encoding.)
All this will set you back about $6,500 and will be available "by the end of 2013."
StudioDaily | Sony Announces Sub-$6500 Pro 4K Camcorder
Sony demonstrated the Z100 for members of the press in New York City last week, pointing the camera out the window of a midtown high-rise. The 4K image was of remarkably high quality given the camera's small sensor size, fixed lens, and aggressive price point.
Live Production TV | Sony Launches Professional PXW-Z100 4K Handheld XDCAM Camcorder
As with the F55, 4K (4096 x 2160, 50p or 60p, 4:2:2, Intra-frame, 10-bit recording in MXF file format) is possible at a high-bit rate of 500Mbps or 600Mbps. QFHD (3840x2160) and HD (1920x1080) resolutions can also be selected, both of which are compatible with most 4K TV’s.
CineTechnica | Sony Announces New PXW-Z100 4K Camcorder
In addition to the standard composite and HD-SDI output, the PXW-Z100 will be one of the first devices to support the newly introduced HDMI 2.0 spec, which means you’ll be able to monitor 4K 60fps over a single HDMI cable.
Sony | PMW-Z100
The PXW-Z100 uses Sony's XAVC™* recording format first employed in the PMW-F55 CineAlta® 4K camera. MPEG-4 AVC/ H.264 compression is used for HD (1920x1080), QFHD (3840x2016) and 4K (4096×2160) content. Image sampling is 4:2:2 10-bit, with an intra-frame system that compresses each frame individually at a maximum bit rate of 500Mbps or 600Mbps during 4K 50fps or 60fps recording respectively and 223Mbps during HD 50fps or 60fps recording. The XAVC format is ideal for those looking to implement a high-quality, secure and worry-free workflow.