It's interesting because both approaches were/are to add value, with PS3 there was BC, BR, built in wifi and HDD, various memory card slots (etc) - "it only does everything" was true. They gave people a ~850 unit for ~600. It was an amazing value proposition. MS have reversed that with XSS and concentrated on the software - next gen should be awesome.
Features only actually add value for a consumer if its a feature they are gonna use. Arguably, a lot of the features of the ps3 went unnused by most consumers.