You can get a raspberry pi with an atheros chipset wifi dongle and you have pretty much a completely open source stack. It just doesn't look very nice to users.

>> Also except for selling openness, what else will sell that you couldn't do today ?

Anything that doesn't fit into Google's technical design / strategy that sells and customers like it.

Android has heaps of preconceived notions about how a handheld should work that are baked into the system and unchangeable.

If you are looking for exact examples of things that are not currently technically possible on android, how about a phone with a gps button widget that doesn't require you to leave the maps app to enable/disable gps or (not that I would personally pursue this) the ability to play video in a distributable app widget.

You don't have to have the processor to be open to do all those, do you ?

And the pi/atheros is open exactly because they're not a mass market product.

Raspberry Pi had sold 5 million devices by Feb 2015. It's a bit different from 7 figures per quarter, but I'd still call it mass market.