My wife would like an MP3 player. There would no doubt be some music played, but the "new factor" driving her to want this device is so she can hear podcasts from one of her favorite radio personalities. She wants to use it in the car, and around the house "docked" into some sort of speaker set. (I say "docked" because I get the impression that only iPods can really dock.)
We run Linux on our home PCs, so it needs to work with it, which may be a factor ruling out iWhatever.
This is something new, and we're not sure how much we really will like it, another factor against iWhatever, which tends to come in at the high side on prices.
I've looked briefly at the Sansa, but there was one comment that it had no bookmark and a nearly useless fast-forward, making it poor for podcasts.
The device should be able to "talk" in native USB-Storage mode, similar to USB sticks.
This is kind of devices, that do not require any drivers.
I have (pretty old, but still awesome) Viruzz MP7 MXII which has internal 64MB as well as external SD slot and both are accessible from all OSes(linux, of course, included).