Just like to say hello as an British Chromecast user.
I've just redeemed another film through www.ultravioletuniversal.com
and I almost wet myself to be given the option to redeem to Blinkbox alongside the usual Flixster option.
It looks like I was lucky with my timing as after choosing Blinkbox I logged into Blinkbox I had to wait for there site updates to reveal the additional UV support.
I now have about half of my collection available through Blinkbox including a few films that were previously only playable with Flixster through a PC.
Looks like this is still WIP as I can watch a UV film through the Blinkbox app on my PS3 but the website errors before I can get chance to play the film.