I received some information from a good source and can confirm that Canon will have a press event on September 5th in Shanghai. There is also a second event in Tokyo on or around September 17-22 where people had to already sign NDAs - this could actually be a factory tour similar to the one from Nikon.
CanonRumors now reports that the new Canon full frame mirrorless camera will be called EOS R:
Nokishita reports that Canon will also announce a new EF-M 32mm f/1.4 STM mirrorless lens.