Search trumps Navigation
|Use application launchers like Launchy, GnomeDo or Quicksilver||Use hierarchical navigation from start menu or equivalent|
|(Coders) Use Ctrl-N (IntelliJ) or Ctrl-Shift-T (Eclipse) to open a class||Use hierarchical navigation of the Package/Project explorer|
|Use search engines to find information on the internet||Might prefer using something like Yahoo Directory to get to the information they seek|
|Use desktop search to find files on their hard disk||Always use the hierarchical file system explorer|
Traditional hierarchical organization requires users to navigate through the hierarchy to get to whatever they are looking for. Such navigation is unnecessary in cyberspace and is painful for seasoned knowledge workers. Reliance on taxonomies is a relic of physical world thinking. Their importance is overrated in a digital medium.
Folksonomies don't replace search either. Being multidimensional, they are useful for finding 'similar content' after you have found the first one. Even then, it requires very good participation by the user community to be relevant.
Comprehensive organization is expensive and time consuming
It takes humans to put things in their place. :-) Correct classification requires some understanding of the subject. At a time when the quantity of content is growing rapidly, it is expensive to hire people with understanding of the subject to maintain a organization hierarchy. Relying on users to do this themselves doesn't work out well in my experience.
Lightweight, deferred organization is easy
One of the problems with upfront organization is that you have to come up with a scheme that is acceptable to most (if not all) users. Instead, it is easy to slap on a starting page or a table of contents later if you are using something like a wiki. When my project wiki began to get unweildy, someone just added a page called "Day one reading material" with links to several other informative pages (thus bypassing all notions of hierarchical navigation). New joiners to the project were simply directed to this page.
Just Ask Around
Asking people for information has never been easier. Corporate microblogging (micro-messaging) tools like Yammer (or just a company wide always-on chatroom) make it very effective and non-intrusive to ask questions like: "Can sometime point me to existing collateral for xyz service offering?"