[T.G]

If it were me, I'd save the original file, because if I were to later discover a transcoding error or other problem in the final output DVD, I can always go back to the original source and remaster. If I've thrown that away, I'm screwed Depending on your transcoding software, image quality can also be lost going from the original file to the DVD output, by throwing away the original file, I've lost my ability to go back and reprocess or examine the source.

It's like shooting still photographs on film at an event. You don't throw the negatives or transparencies away after you've printed the event book or photo album.

Also, if you ever need it for legal reasons, having the raw file available will be of some comfort if the authenticity of the original footage has to be proven along with that it has not been edited or tampered with.