Running Firefox 43 here. Either I'm doing something wrong or it's not compatible with my installation of Firefox. I've opted in for HTML 5 video, but when I attempt to play a news video, I am still prompted to install Flash Player.
As an aside, am I crazy, or is it weird that neither the blog page or the opt-in page embed a video for testing or even link to a video for testing? I don't know where to find an instance of "iPlayer" on the BBC site (on the off chance that's different than the video player they use for news items).
I searched for what one might call a traditional television program on their home page, but that didn't work either. I clicked the play icon on the "Featured Video" on the home page and was again prompted to install Flash.
I'm happy to hear about the effort, but not yet thrilled with the results.