What is the opposite of quantization? Is the opposite of quantization just taking the limit $h \rightarrow 0$ ? Or are there more steps involved (maybe related to bosons and fermions?)? How would one call the the opposite of quantization? Classization? Continuization?
 A: The term "dequantization" is used in other domains, and apparently in this context (e.g. in the preface to  Quantum-Classical Correspondence: Dynamical Quantization and the Classical Limit, Bolivar, 2004, or in Variational approach to dequantization, Mosna et al., 2006). 
I do believe the question might deserve more context, in other words is the question well-defined? There is a discussion in Classical Limit of Quantum Mechanics, and the beginning of Decoherence and the Classical Limit of Quantum Mechanics states that:

There is also an enormous amount of mathematical work, called
  semiclassical analysis or, in more modern terms, microlocal analysis
  (see, e.g., A. Martinez: An Introduction to Semiclassical and
  Microlocal Analysis, Bologna (2001)),  in which the limit $\hbar \to
> 0$ of Schr¨odinger evolutions is rigorously studied

and then asks

What is the relevant physical quantity whose convergence “in the
  classical limit” asserts in a satisfactory way that the classical
  world arises?

A: Even in the old quantum theory, prior to 1925, to transition to the classical limit, known as the Bohr Correspondence principle, one doesn't let h -->0, but instead n --> Infinity.
