I'm thinking of biting the bullet and doing the Google Play Music thing. I'd have to upload my itunes collection to the cloud (a good thing, in the long run). But I'll be able to have my music everywhere with a 3g or wifi connection. It can be set up to automatically upload any new items added to your itunes library. And you can download songs to your phone for offline listening.
The one drawback for me is that both me and my girlfriend also have Kindle Fires and we would have to mess around with rooting or some other type of workaround to get Google Play to work on those devices.