Not much response here, but it turns out there's a forum over at Sandisk (I think it's at sansa.com). Apparently, there are two modes the Clip can work in -- MSC and MTP (or something like that). One mode is required if you want to play DRM protected music, and it doesn't work on linux or look just like a hard drive.
The other mode makes the Clip look just like an external drive and you can drag (non-DRM) music back and forth with no issues, as well as other file types. It supposedly works fine in linux and on the Mac.
I have a Sandisk Sansa E140 (ancient, I know, and no, it doesn't require stone chisels or anything to get music on it). Anyway, I'm thinking about getting a Sansa Clip for the extra storage (8GB, whenever they are really availabe. Right now, I have the 1GB player with a 2GB SD card).
One of the things I really love about the E140 is that it just looks like an external drive. There is literally no extra software needed to load it up, there is no requirement to set aside some portion of the player for data if you want to use it to transfer non-music files, and it works fine with Windows and Linux -- just plug it in and move songs to it.
Do the new Sansa players (especially the Clip) work the same way? Or, do they have to interact with Windows through some media protocol, like the Creative players do?
If it's the latter, how much of a hassle is that media protocol? Does it prevent players from working with Linux?