I think a good feature for when the DeviceNotifier fails to unmount a drive because it is in use, should list the processeses that are using the drive, (and perhaps resolve the process names with an application icon like ksysguard can.) Right now, users have to guess, or use fuser. It is my understanding that it uses the udisks backend? I don't know if udisks has this functionality though... This was https://bugs.kde.org/show_bug.cgi?id=317571 in KDE 4
It does.