I have one, it's a pretty nifty little device. I'd echo what ylexot said, for now the functionality is pretty limited. But that will likely change in the not-too-distant future. I find that what it does, it does pretty well. And the price is right.
I use it mostly for Netflix. It made for a nice solution for my bedroom TV which is mounted to the ceiling in a corner of the room and has nothing connected to it. It allows me to have a clean set-up (i.e. no boxes or DVD players, e.g., that have to sit somewhere and have cables running to the TV) with that TV and still use it for Netflix. And, especially if you're using TVs with a USB port that can power it (i.e. not a service only USB port), it travels well and allows you to quickly set-up other TVs to use it. It turns pretty much any modern mobile device into a remote for selecting Netflix, YouTube, and Hulu content on a TV.