iPod nano not iPod OS, not iOS, something new?

Is it possible the new iPod nano isn't running iOS, but isn't running the old iPod OS, either? The latest firmware has hit Apple's servers so developers are tearing into it and here's what Steven Troughton-Smith had to say on Twitter:

The nano codename is N20 it appears; also labelled as "1.0" of the OS. Definitely not iOS

Rusty Mercury also says it's running on a Samsung S5L8723, a step up from the previous Samsung S5L8723.

So what is this OS 1.0? something new? Something hybrid?

[@stroughtonsmith via 9to5Mac, @RustyMercury]

Rene Ritchie is one of the most respected Apple analysts in the business, reaching a combined audience of over 40 million readers a month. His YouTube channel, Vector, has over 90 thousand subscribers and 14 million views and his podcasts, including Debug, have been downloaded over 20 million times. He also regularly co-hosts MacBreak Weekly for the TWiT network and co-hosted CES Live! and Talk Mobile. Based in Montreal, Rene is a former director of product marketing, web developer, and graphic designer. He's authored several books and appeared on numerous television and radio segments to discuss Apple and the technology industry. When not working, he likes to cook, grapple, and spend time with his friends and family.