Just free-thinking here, off of Dana's post . . . but what does the interface of the Linux-formatted Mini look like? Is it replacing the Mini's OS with an open-source one, or is it only changing the file system used for storing files? Does it use that clever spin-the-wheel and push-the-button menu system?
It's an interesting question of whether Apple could achieve copyright or patent protection for the interface on the Mini. Regarding copyright: is the Mini's interface covered under merger, as the windowed OS was held to be in Apple Computer, Inc. v. Microsoft Corp., 35 F.3d 1435 (9th Cir.) (casenote at 1 Rich. J. L. & Tech. 5 (1995))? Is there really effectively just one way to interface with an iPod? It could be, considering its extremely-stylized configuration. Of course, there are likely design patents at issue here, which gtkpod may infringe.
Not that any of this is easy to enforce against an open-source community, but I'm sure someone at Apple legal is thinking about this.