I agree with this. Having an OS option to scan and tag your documents into some taxonomy that is a built-in in your file browser would be quite attractive. I'm sure Microsoft and Google are both working on it.
e-Discovery applications like Relativity have been doing this for years. You run a PCA against a bunch of OCR'd documents, look for correlations between words or phrases within documents, look for repetitions of those particular correlations, call them 'issues' or 'motifs' and slap a label on them. Attorneys used to use it to scan millions of documents in a discovery set and auto-flag them for possible privilege issues for further review, and even automatically mark them as such.
e-Discovery applications like Relativity have been doing this for years. You run a PCA against a bunch of OCR'd documents, look for correlations between words or phrases within documents, look for repetitions of those particular correlations, call them 'issues' or 'motifs' and slap a label on them. Attorneys used to use it to scan millions of documents in a discovery set and auto-flag them for possible privilege issues for further review, and even automatically mark them as such.