My cousin, who was originally supposed to be flying LHR - SYD on Qatar this coming Wednesday, was bumped off her flight on Thursday. Next available flight in mid September. She's now rebooked herself on Singapore for tomorrow, fingers crossed.
I have asked earlier in this very thread about EC261 but no-one seems to know anything about how it works in these situations. I get the impression that the airlines are simply ignoring it.
The whole purpose of this thread is how to avoid being bumped. In principle it shouldn't be happening but it is still widespread.