These OSs are not built in the context of them being used as a desktop platform, rather as an easier way for developers to develop (developing on your native platform is much better than developing off a remote completely different machine). I am skeptical that anyone could even actually make these boxes actually provide what desktops can provide, and this is what all those people working on porting think. The constraints of game console architecture are way too large for them to be decent operational general operating platforms.

Linux has always been the development operating system for the commercial SDK, it wasn't until later last year Sony decided to release a garage developers edition for hobbyists.