The thing with NOSQL is that it is not a single thing, it's a massive range of things.  Each one is intended to solve a particular problem.  The trick is to understand which problem they are designed to solve and then do an honest assessment of
a. Do you have the problem
b. Is the problem big enough to be worth solving
C. Will solving it cause much bigger problems elsewhere (most likely with integration)

In the analytics world ORC & Parquet formats are becoming more prevalent.  These use column store techniques to achieve acceptable performance.  Parquet allows nested structures in the same way that Postgres has an array data type.
The question I have is at what point do the facilities in SQL Server fall into the NOSQL camp?  MDX? Full-Text search? XML?  JSON?