The Raspberry Pi streams 1080p video and the whole thing costs $35. $70 with a power supply, enclosure, cables, and SD card, and that is splurging on some of the above. You can do a lot for very little money in computer hardware these days.
Love the Raspberry PI, but its probably safe to say that the computing power contained in the next gen consoles is going to be at LEAST 10x what the PI has in it.