Except that in your example, each new generation doesn't obsolete the prior generation when it's released. MP3 players? I still have an old Rio 500 from 1999 that will work with MP3 files ripped or sold today. Cellphones? How long has it been since a network upgrade killed old cellphones? TVs? Next year's switch to digital TVs will obsolete old ones, unless they get a converter box... but that's been the first major format obsolescence since color TV came in in the 1960's. How many of the consumer electronics devices you name above follow the specific 770 situation, where the manufacturer killed off compatibility between generations?

Heck, how many years back does software compatibility go in the Palm lineup? I think current Palm software will run on units going at least as far back as the Tungsten T, which was a 2002 release...