[jayruy]

The article is so vague it seems even the author isn't particularly sure of the point.

Notions of factor models and hidden markov models have been around in the statistics literature for ages. Computer science's contribution to the discussion has been framing these methods as machine learning - and leading the foray into unsupervised learning. But I'm not sure if unsupervised learning techniques are being put to use in real-world data analysis, I believe the theoretical foundations are still a bit opaque.