New IE updates in latest Windows 10 preview build. Still no Web Audio but they assure us it's coming! :D http://blogs.msdn.com/b/ie/archive/2014/11/11/living-on-the-edge-our-next-step-in-interoperability.aspx

I was a little disappointed that the "IE dev channel" from a few months ago never got updated, but updates seem to be coming at a reasonable pace in the Windows Technical Preview now, which makes me a happy webdev panda.