  Let G be a finite group acting on a symplectic complex vector space V. Assume
that the quotient V/G has a holomorphic symplectic resolution. We prove that G
is generated by "symplectic reflectionsd"', i.e. symplectomorphisms with fixed
space of codimension 2 in V. Symplectic resolutions are always semismall. A
crepant resolution of V/G is always symplectic. We give a symplectic version of
Nakamura conjectures.
