I hope it's on the way, but I don't think the Pioneer Na is yet a sign of this revolution. This detailed review didn't leave me in a hurry to go get one, anyway:
The idea with really cheap batteries is that they don't need good energy density. You just swap them every so often and put the one you aren't using in the charging rack. You could even carry your own reserve energy with you!
We used to have swappable batteries in virtually all of portable electronics. You could even get them in a rechargeable accumulator format. Virtually all of portable electronics has integrated batteries.
Yeah but AAs suck, and the newer more advanced batteries all have different voltages and require different charge circuitries so it’s hard to create a new standard for them.
A circuit that accepts the voltage range of lithium ion is probably 90-100% of the way to accepting a range of cell chemistries. And you can put in a half cent identifier chip to say what the charging voltage is.
I don't think the technical difficulties are the problem here.