Dewey out of date?

David Weinberger comments in his book Everything is Miscellaneous that the Dewey decimal classification system is out of date and I am inclined to agree. Studying the mentality of Dewey through his subject headings has left me with a feeling of going back in time. So this leads to an important question. Is the Dewey decimal system worth updating? Or should we develop a new system? More importantly, how do we even make that decision? If the world of information is always being transformed as Weinberger so bluntly states towards the end of his book, how do we react to this transformation? He further states that traditional knowledge changes by staying the same. Which makes me question how do we determine what is traditional knowledge versus what is nontraditional knowledge? I suppose this would depend on several factors, one of which being the field of study that is in question. In library science, what would be considered traditional knowledge? Would the Dewey decimal system apply? If so, is it changing by staying the same? Is it alright to change this traditional knowledge? Some could argue that by staying the same it isn't changing enough to fit with the changes brought on by time and social expectation.