It would be nice to see more of iOS open sourced. Not everything, but enough to run the GUI and maybe Safari.
I think that could be a huge win for Apple. Lower end, open source iOS compatible phone could attack Android offering, particularly at the lower end. They'd gain control over the market (as it would be derived from their source, and compatible with their ecosystem) without having to do much work.
Honestly, if Apple don't do it, someone should come up with an open source iOS compatible offering, which developers could easily re-target their apps to.
VCs reading this, I'm offering 15% for 3MUSD for the above idea. ;)