Canon Watch was the first site to report that Canon is working on a full-frame mirrorless camera. Now some more tidbits point in this directions. It’s suggested that
Canon will “surprise a lot of people” with one of their next mirrorless camera
While this new rumor doesn’t explicitly mention a full-frame mirrorless camera, it’s likely that only such a camera could surprise us. The same rumor also suggests that Canon will “no longer playing catch-up” in the mirrorless domain. That Canon is willing to get serious with mirrorless was also posted first here on CW.
The latest reliable rumor I got about a Canon full-frame mirrorless camera dates back to November. It was suggested that Canon’s FF mirrorless camera is delayed because of mount-related issues.
All rumors about a Canon full-frame mirrorless camera are listed here.