Here's the quote from the Microsoft employee who did an AMA and mentioned the Xbox Music app.
You know what, It’s not what I wanted but HOLY **** I can now download music I own, create a playlist, and add XBOX Music to the same playlist… and it works!!!!
No skipping. But I probably have a pre-release app. Apps I can’t really talk about. I have no idea if they are final, close to final, etc. I work on Windows Server and the Windows Kernel. I do things like play with bootmgr, network boot (no disk, boot over the internet into windows, no problems), etc.
One thing I like taking away from his comments is that it sounds like we can download music now without having a music pass, and not needing to sync to a computer.