OK, I’ll bite.
It has line in (so you can record MP3s on it directly from source), line out (plug it into your amp), displays photos and .AVIs.
What’s not to love about it?
A friend of mine has one and I borrowed it for a day, then did more research: there’s [rev engineered] software for it for Linux support; it does show up as an external harddrive but you need to generate an iRiverDB file so you can search for files on the fly.
Methinks I’ll definitely will be getting one.