US->UK adapters are ok.
But I have issues with mine as the slightest bump and adapter disconnects. It's probably a case of needing a better adapter. But a UK plug would be great.
Perhaps a power adapter that took a standard power cable as per a laptop or desktop would be terrific. That way we could great a cheap cable from our local shop (or cupboard) and plug it into the power supply.
I also worry that the odd 3 pin socket will be a pain if the power supply goes "pop" in the future. Where else are we likely to be able to get that sort of power supply and socket.
Love the unit though! Zonbu, you have already saved me many hours of support here at home! My none technical housemates are able surf the web (including YouTube) and have not hassled me once about problems... well except for when they bump the plug and the Zonbu turns off.