Anyone aware of any promising client-side solutions for responsive images?

I'm hoping to see something like the picture element suggested here:

http://www.smashingmagazine.com/2011/11/html5-semantics/

<picture alt="angry pirate">

   <source src=hires.png media="min-width:800px">

   <source src=midres.png media="min-width:480px">

   <source src=lores.png>

      <!-- fallback for browsers without support -->

      <img src=midres.png alt="angry pirate">

</picture>

Would something like this be possible to implement with React or Web Components? Or will we have to wait for HTML6?

In my opinion, responsive images really shouldn't be a server-side concern, much less something that should require a third party service.