I've always thought there was a massive potential for a "consolized" PC platform. Standardize the hardware, lock into just a few resolutions (720 and 1080 probably), and streamline the OS for the gaming experience. Possibly modularize the hardware to allow for some easy incremental upgrades along the way (such as a GPU module).
I suppose something like Windows 8 could be molded to be an optimized quick-launch operating system, but it might be too clumsy to fit the simple gaming console concept. I have pondered a stripped down and customized Linux gaming build in the past, that could provide an "instant on" feel, would be able to portal to something like Steam as the default, and could still provide some of the basic HTPC functionality when desired (basically like the PS3 before they axed the "other OS" options)... Other than the whole issue of porting everything to Linux, that is. Bleh.