In the P2PSP team we think that a Google Chromecast device can run a P2PSP peer and a player using the WebRTC framework. Chromecast has a Chrome browser inside, that is the reason to think that HTML5, MSE and WebRTC are available. So, an implementation of the P2PSP for the web browser would be compatible with the device.
This is the idea that we presented in the JCE "Jornadas de Computación Empotrada" (Embedded Computing Conferences), held in Córdoba (Spain) on September 25. We want to get a beta version soon, but for the moment...we are working on it.