“Not really sure what you mean by ‘what are they thinking.’ Of what benefit would it be to Sandisk to give code to the Rockbox team?”
For one thing, Accessibility for blind and severely visually impaired would be enhanced, I understand that Rockbox has voice navigation. For another, given that Rockbox seems to be taking over the world, it’s a big favorite with the folks at LibriVox (which is sort of tied in with Project Gutenberg and Internet Archive) it makes sense to get on a train that’s going somewhere and fast. What sense did it make to get involved with Yahoo!, which is about as stable as Birnham Wood, which MacBeth thought would never come to Dunsedain. It might be good to get in tight with Google/YouTube. I think Yahoo’s days as a big player are numbered. They should find a niche and lodge therein.
The proprietary chips may be a different matter, however, an appeal to self-interest does wonders