Whoa now, I would not keep your hopes up..
See Andre's post about frequently requested features, specifically:
- Library access to local sources (e.g. playback of songs from home DLNA or NAS servers, SMB/FTP access, etc).
- Library access to users' cloud sources (e.g. playing your music from Google Drive, Dropbox, or other online locations).
- Access to commercial streaming services (Spotify, iTunes, Amazon Music, YouTube Music, etc). <-- Note: unlikely to happen due to licensing restrictions
The first two ever materializing is plausible, but no clear sign of when.
The last point sounds like what you're asking. As I said, get cozy waiting for that one ☕.