As I understand it, the dictatorship of the proletariat exists with the worker's state. The dictatorship of the proletariat refers to the control (dictatorship) of the state by a new class (proletariat as opposed to bourgeoisie) and this is the form of government a worker's state possesses. The worker's state has not achieved socialism yet, but is actively working towards a socialist society that will shrug the "state" in the phrase worker's state off.
"The image of the universal 'Proletarian,' who strides forth from the earth to conquer planets and stars!"
"The Earth is the Cradle of the Mind—but one cannot eternally live in a cradle." - Konstantin Tsiolkovsky