Something else I remembered; these advances are taking place via the application of sound scientific principles, discipline, and good old-fashioned hard work.
To the best of my knowledge, End-Timers (JW or otherwise) have virtually always interpreted the fulfillment of Apocalyptic/Millenial prophecies (positive and negative) as being overtly "miraculous" in nature; i.e. supernatural phenomenon.
Advances in longevity medicine, disease elimination, stem cell therapies, cybernetics, and nanotechnology (not to mention climate change and Peak Oil) are all, despite being astonishing (or extremely worrisome), distinctly mundane, "real-world" things. If humanity accomplishes this much on its own without divine assistance (or judgment), it's potentially a huge blow to the fundamentalist worldview.
That reminds me, I remember chuckling when I realized that the majority of advances and more importantly, successes - in genetics therapy are, in a big way, due to the application of evolutionary models to the research.