This is a coincidence, just yesterday i checked out Cordova, Ionic (on todo list, but the demo's on the APK's seem to slow :s), Supersonic seems quite interesting also (and a lot easier then Polymer)!
Yup, Polymer is doing exciting stuff – the declarative native UI components in Supersonic are actually implemented using web components (meaning they're really framework independent), and we utilize their polyfill since the web component spec is not supported in browsers yet. You can see the source code at https://github.com/AppGyver/supersonic/tree/master/component...
We didn't embrace Polymer more fully for various reasons (like it being a very WIP project still), but the Polymer web components should all work fine with Supersonic apps.
But what really interested me are the demos from Google (Namely Paper Elements as UI) with Polymer (it's like AngularJS, but it isn't): https://www.polymer-project.org/docs/elements/material.html
Fyi, an index of webcomponents for polymer is available on : http://customelements.io/
There's a designer tool for it: https://www.polymer-project.org/tools/designer/ , here's how to use it http://goo.gl/r8ovXN (it's a responsive maps application, with search input and speech input)