[Brightcolours]

The Canon R3 will have a high resolution sensor (like the R5 and the Sony A1), offering oversampled 4K. Also will offer Canon Log3 4K and internal RAW video recording. While the R5/6 already have best of class AF, the R3 will offer even better head, face and eye detection, animal body detection, vehicle subject recognition and tracking for cars and motorcycles.

It will have wired LAN and 5GHz Wi-Fi capability built-in. It will use the LP-E19 battery (that is what the 1D-X II uses) and feature a new hotshoe design with options for data communication and power. It will offer upto 8 stops of IS (combined IBIS and lens IS).

[Brightcolours]

The Canon EOS R3 will "only" be 30.1mp (BSI and stacked CMOS), with high speed 30 frames per second shooting with AF and AE, in RAW. Internal RAW video recording, oversampled 4K and Canon Log3. 8 stops IS with IBIS + certain lenses with IS. Official announcement on june 29th.

[Rover]

"Only" 30MP. *snicker*
BTW the one stat I don't wanna learn about is the price. I know for sure it'll be "too much" for me and many/most others. (tho not for Ken Rockwell who has recently proclaimed the Nikon 58/0.95 "a bargain at only $7997").

[Klaus]

So 30mp, no 8K.
https://www.canonwatch.com/canon-eos-r3-to-get-announced-on-june-29th-2021/

[Rover]

Gotta love the commenters.