Craig suggested this once, everyone seemed to be all for it, but it really does breakdown when you look at it deeper.
Why would someone buy a Pandora desktop when they can most definitely get an Ouya, RasPi, or BeagleBone for much, much cheaper? What benefit does the Pandora have over anything else? It has portability, substantial battery life, good controls and keyboard (for a handheld). But the instant you start talking about tethering it to a TV all of those benefits disappear: it's no longer portable at all, it doesn't need battery life, and you can easily grab any controller and keyboard you want.
There may be room for yet-another-open-source-console, but simply taking the Pandora and plugging it into a TV wouldn't be it; it would need to be redesigned as such, removing the battery and keyboard, and then you're not really designing anything that can be called a handheld console anymore