According to The Verge, Microsoft will be showcasing off their new music service during E3 this year. Woodstock, the code name for the project, is an attempt to move on from the Zune franchise and use the XBOX 360, a more familiar device, instead. The service will also be able to be utilized on different platforms on a browser. Windows 8, Android, iOS, and of course XBOX users will be able to, hopefully, enjoy Woodstock on their systems.
Microsoft's new music service will not require browser plug ins and will, unfortunately, be heavily integrated with facebook. Make sure to heavily protect your information kiddies (that goes for you too parents). The product will also feature a capability that will identify the music you currently have in your collection. Whether this means that you will be able to listen to the music you own for free using this system is up to speculation since Verge did not mention anything else past that.
Woodstock is not expected to launch until later this year around the release of Windows 8.
Source: The Verge