When I use n-gdu on a blank DVD+R, it tells me bunch of not really helpful things about the medium:

Unknown Size
Unrecognized
Connected via SCSI
/dev/sr0


I don't think any of this is useful information in a 'friendly' formatting utility. If the size and current filesystem were known, that might be useful information to display, but "Unknown Size" and "Unrecognized" is not. And if the device is connected via SCSI and what its /dev entry is really have no relevance to the average user trying to save some stuff on a cd.