As for me, this is important and highly important for those who want to do research in digital forensics.
So, how are we going to conduct a research if the description of digital forensics is still vague?
I don’t know if you have read this paper, “A Comparative Study of Forensic Science and Computer Forensics” . This paper creates the interest to ‘investigate’ more on digital forensics itself but not conclusive (got future work).
Another one is this, http://computer-forensics.sans.org/blog/2009/06/04/is-digital-forensics-a-science/.
And according to Wikipedia, scientific method refers to a body of techniques for investigating phenomena, acquiring new knowledge or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry must be based on gathering empirical and measurable evidence subject to specific principles of reasoning.
If you read the second part of Wikipedia definition, you might be relief but some people might create another issue or question it again (just to be polite here, not assertive).
There is another paper that I read, "A comparison of forensic evidence recovery techniques for a windows mobile smart phone" . This is another informative and good reference paper for the practitioner and also researcher.
Well, if you are entangled or over zealous whether digital forensics is science or not than you might question everyone’s papers, e.g. . But to me  is very important. There is a lot of ‘knowledge’.
My Mac Book Pro Dictionary says:
Science - the intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment.
Hence, isn’t that digital forensic a science?
Is digital forensic ever going to be technological engineered? The tools! Or merely reverse engineering.
The word forensic already means science! What the fuss?
Or is it an art (there are so many ways of doing it)?
It seems that digital forensics is a science, engineering and…an ART.
The keyword is empirical.
What say you?
P.S: Btw, I admire Leonardo da Vincci.
(1452–1519), Italian painter, scientist and engineer. His paintings are notable for their use of the technique of sfumato and include The Virgin of the Rocks (1483–85), The Last Supper (1498) and the Mona Lisa (1504–05). He devoted himself to a wide range of other subjects, from anatomy and biology to mechanics and hydraulics: his 19 notebooks include studies of the human circulatory system and plans for a type of aircraft and a submarine.
 R. Hankins, T. Uehara, and J. Liu. “A Comparative Study of Forensic Science and Computer Forensics.” Third IEEE International Conference on Secure Software Integration and Reliability Improvement, 2009.
 G. Grispos, T. Storer, and W. B. Glisson. “A comparison of forensics evidence recovery techniques for a windows mobile smart phone.” The Journal of Digital Investigation, pp. 23-36, 2011.