It's true that both the Bush and Obama administrations introduced government subsidies in industries that the government has not historically subsidized to the same extent, but this is not, strictly speaking, a socialist move because it does nothing to concentrate power over the businesses in the hands of workers, nor have the government subsidies even begun to approach a scale that would satisfy even the most flexible definitions of socialism.
In order to be a socialist, Obama would have to favor the large-scale collective ownership of private enterprise and the redistribution of wealth based on labor. The fact that he supports some policies that reduce the relative power of the rich, and increase the relative power of the poor, does not make him a socialist by any useful standard. It makes him, at most, a social liberal--though given the degree to which his policies still allow for the consolidation of wealth, he isn't a very good social liberal, either.
Socialism represents a radical departure from the current economic system, and transforming the world's largest, most fundamentally capitalist economy into a socialist system--assuming this is even possible--would take decades of intricate, carefully planned policy work at a federal, state, and local level. It's not something that's going to happen accidentally or secretly over a period of four years. A few more corporate bailouts, tax increases, and social welfare policies won't do the job, and nothing Obama has proposed on a policy level would do the job. Nothing short of a complete reconstruction of the U.S. economy would do the job.
This is not to say that Obama is a pure capitalist either, but no president in U.S. history has been. Even George Washington supported the creation of a federally-managed national bank. Pure capitalism, like pure socialism, only exists on paper.