Tags are obviously very helpful in organizing files across folders hierarchy. But the effort needed is not insignificant. So any solution for the problem requir

Tags are obviously very helpful in organizing files across folders hierarchy. But the effort needed is not insignificant. So any solution for the problem requires at least two features: easiest as possible for tagging new files (least mouse clicks + key presses) and automatic tagging. The first part requires a superb designed UI with lots of customization options. The second part can be built using plugins, regexs rules and content classification. I can envision even an open market for the second part. IMO, the biggest question is however, whether a big enough demand for these kind of file management exists.