It is meant to be announced later today, and things have leaked already...
Leaked (translated) specs:
Micro 4/3 Live MOS Sensor
Image plane phase detection AF
Internal 5.7K 60/50p 10bit recording
ProRes 5.7K & ALL-Intra 800Mbps via USB-SSD
Anamorphic Mode 5.8K 30p 10bit
Burst 75fps AFS – 60fps AFC
For everyone that wanted a PDAF GH5 v3, this looks like it.