Fast charging startups are popping up all over the place in Europe. Furtest along is Fastned with 50 locations with 50kW DC charging which they will upgrade to 150kW next year. The Swiss fast charge startup Go Fast recently powered up their first location with 150kW charging too with plans to expand rapidly. Allego is on track for 350 fast charging sites all over Europe (mainly Germany) by the end of this year. They too are part of CharIn, so I'd expect them to have 150kW capabilities by the end of 2017 as well.
At least in Europe Tesla is still well in the lead but alternative fast charging solutions are coming online rapidly enough that I'd estimate the lead to be no more than 2 years. Obviously in those 2 years Tesla will expand too, but it is not impossible that by the end of 2018 there are just as much non-Tesla 100+kW fast chargers than there are superchargers.
In my opinion, Tesla's lead in electric cars that actually can take advantage of true fast charging is larger than it's lead in fast charging infrastructure. At least for Europe.