Excited by the EMI/Apple announcement of imminent DRM-free downloads, I checked whether my audio player -- an iAudio M5 -- could play the AAC format that Apple sells. I found that it couldn't, but that the open-source Rockbox player software, which can, has recently been ported to the M5.
I've installed it, and it works. I like the plugins - there's a chess program, and a sudoku. The metadata database feature doesn't seem to work, and the interface is sometimes slow to respond, which is irritating. (It can take a couple of seconds sometimes for a submenu to come up, and if you've repeated your selection, the extra events then take effect afterwards).
These are quibbles; I'm very impressed with rockbox. I'll dig into the database issue over the Easter weekend, and maybe come up with some patches if I can work out what it's supposed to be doing.
There are other obstacles to taking advantage of the Apple thing: there is some question as to whether rockbox can play 256kbps AAC in realtime, but I suspect on the M5 it can, as it has a more powerful CPU than some of rockbox's older targets. I also understand you can't just buy iTunes from the web, you need to install the software. Apple may change that, or I might be able to get it working with Wine.
There is also a question as to whether the iTunes offer is value for money. I currently get music by buying CDs from the likes of Play or 101cd, typically at GBP5-8 each (very little music that has come out in the 21st century has interested me). I will try it out if I can, just because it's a step that has to be encouraged.