I was working on my own pogoplug client for WP8 using the public API. the app is published to the market place now http://www.windowsphone.com/en-us/store/app/pogoplug/61eef542-cefb-4cf3-8154-b3ecfddc7cfd
at present you can browse files, view images and videos. Let me know the features and updates you would like to see and I'll try to add them if possible through the public API.
I hope pogoplug releases an official app soon.