What factors will satisfy us that blockchain technology is on track for realizing its potential?
Because as of now we see very little in the way of commercial and user engagement...
we need and only care about bitcoin success and for that we only need more adoption and it will only happen over time and with some other factor.
the underlying technology (the blockchain technology) is successful and is becoming a lot more successful as bitcoin grows bigger. besides there are lots of people, groupls, and banks working on the technology with all their altcoins, so i'd say it is pretty successful.