Add files from Dropbox, UPnP devices or iCloud Photo Library (iOS)
Share files with other UPnP devices (*2)
No support for DRM-encrypted media (*3)
(*1) Many videos are restricted from being played outside of youtube.com (mostly music videos)
(*2) Cannot share/host files on iOS devices because of limited local/persistent storage
(*3) For example: WMDRM (WMA), CSS (DVD), AACS (Blu-ray) etc.