This article is rather insightful in terms of the challenges that NFC faces in high traffic situations that one encounters in day to day life.
Also, implicitly it highlights the impact of decisions (such as placement of the secure element) on the customer experience. Furthermore, the notion of TSM needs to be ironed out and the options whittled down to make the overall approach particle.
Based on the current perception, it would probably be fair to say that the initial estimate of ubiquitous acceptance in the next 2-3 years is more like 3-5. The caveat would be the emergence of a player (like Apple) that can standardize the current standards based proprietary extensions with one path forward. Ofcourse, as Apple has demonstrated it may resemble a closed system, though makes for a consistent experience and a modular way for the ecosystem to plug in to (once Apple gets its cut).
Interesting times indeed.