The conventional wisdom (always suspect) is that portable devices will converge on a single platform. In the future we will each carry a single device that is a phone, clock, radio, camera, media player, media recorder, messenger and provide all the functions of a PDA including calendaring, reminding and note taking. This is called convergence.
Well as the song goes "it ain't necessarily so". I have written about this before, however I got to thinking about this again when I wanted another track on my iPod. I use the iPod Shuffle to listen to podcasts. Sometimes, I would like to have a second music track for when I want to concentrate and need background music to drown out distracting sounds. Time to trade up to a more sophisticated iPod? Well the alternative is just buy another iPod Shuffle, after all they are cheap enough and I can have one Shuffle with podcasts and one Shuffle with a music mix.
The point is, the devices are so cheap that there is no need to have one converged device. In fact you may be better off with several best-of-breed devices rather than one mediocre do-it-all device. Hence divergence. In fact convergence may be the new disintermediation.