These platforms that we call smartphones are far from what is considered "embedded" these days. To reach the blurring point between "embedded" and "phone" from the industrial perspective you either step through the looking glass into the realm of the baseband (where vxworks or some other RTOS rules the day,) or drop down under 16MB of RAM into the dumbphone world where they are trying to wring every last cent out of the system.
At the level we're working at, and with the hardware in these platforms, string parsing is totally trivial and you're better off working on minimizing wake-ups and overall power saving.
dbus is common across Linux platforms, and has its own maintenance team. I'm not quite sure what you mean by a "shell interface" though.
It's unlikely you'll ever see raw NAND in that quantity. The eMMC interface simplifies system bring up so much it's ridiculous.
openWRT is awesome, but with only 8MB of storage in my WNDR3700 I can't do a whole. In fact, I only have 1MB free and there's more I'd like for it to do, which will probably involve me performing acrobatics (or contortions) to make it boot from an external 8GB USB stick.