Wireless Music

So, I've been trying to find an alternative to Airtunes (airplay also I guess) for Android and so far have come up with nothing. Does anyone know of anything that it similar to Airtunes for Android?

Here's what I would like to be able to do. With any iOS device and an Airport Express, you can redirect the audio stream coming from that device to the Airport Express and play music wirelessly (you can also do this with Apple TV). Now, I realize that there's not going to be anything exactly like that for Android, but I really just want to stream Spotify to my stereo wirelessly. I have a Nexus 4 & 7, an Airport Express, and an Xbox 360, and I'm willing to buy stuff to make this happen. My stereo receiver is from the 90s so no networking or usb, but plenty of types of audio inputs.

I really hope this is a feature of Miracast, because this is a pretty big omission from Android. Airtunes has been around since 2004, and 2010 on iOS, and Android has nothing to compete with it yet (that I've been able to find..).