Microsoft has been updating a lot of Windows 8 application recently. Now its the turn of Xbox Music. The update brings performance improvements on the RT side, making it a lot more usable on devices like the Surface RT. Additionally, there an independent volume control, which makes playing music in the background a lot easier.
I still think that Microsoft has missed yet another trick with Xbox Music. I find the application very hard to use with poor navigational options within the user interface. With all the Windows operating systems available mixed with Xbox consoles, I really thought this was a big win for Microsoft!