Canon has officially announced the following features of the EOS R3:
• New multi-layer back-illuminated CMOS sensor developed by Canon
• Capable of shooting 30 frames per second with AF / AE tracking
• AF tracking of people, animals (including birds) and motorsport (racing bikes and racing cars)
• Can record 4K / RAW videos with internal oversampling and Canon Log 3
• Eye Control AF Point Selection
• Capable of focusing at light levels of -7EV or below.
• Dual-Pixel CMOS AF
• Dust and water resistance of the case as in the EOS-1D series
(from the site usa.canon.com)