Streaming music from OneDrive should be a no-brainer for Microsoft; however, the ability has been rumored for months and we have yet to see anything. New word says that we may finally be closer to an actual release. Text from the Xbox Music web app has alluded to the possibility of a new 'music locker' service in the works.
Presumably this feature would enable users to have access to their entire collection of music -- even songs which are not currently on Xbox Music. It is unclear if Microsoft will require any separate app or subscription to enable this service, as this can be more legally challenging than technically challenging. The code does reference a 'locker app' but it is unclear if this is just a part of the Xbox Music app, or if it will be separated.