In the one-dimensional case the Langlands program is equivalent to the class field theory and the two-dimensional case implies the Taniyama-Shimura conjecture.


I would like to know: are there any other important consequences of the Langlands program?



Consequences of the Langlands program
There are many, many consequences of the general Langlands program (which I'll interpret to mean both functoriality for automorphic forms and reciprocity between Galois representations and automorphic forms). Some of these are:


* The Selberg $1/4$ conjecture.
* The Ramanujan conjecture for cuspforms on $GL\_n$ over arbitrary number fields.
* Modularity of elliptic curves over arbitrary number fields. (Indeed, Langlands reciprocity
is essentially the statement that all Galois representations coming from geometry are attached to automorphic forms.)
* Analogues of Sato--Tate for Frobenius eigenvalues on the $\ell$-adic cohomology of arbitrary varieties over number fields.


