Since when can corporations cast votes?

So I am watching Keith Olberman ranting about the fact that "major news organizations" were too busy reporting on John Edwards' love child" and basically ignored the Supreme Court striking down the McCain-Feingold Campaign Finance Reform legislation by declaring that Corporations are essentially "ENTITIES", and as such as entitled to free speech under the constitution?

I am speechless. I am thoroughly convinced that the U.S. government should be declared legally insane. What do our tax dollars get spent on? One branch of government circumventing the will of another branch of government. And the tax payer once again gets the shaft. We can now count on corporate interests subverting every campaign they can with their dollars.
Perhaps they'll use the money they saved on raising working womens wages to match male workers wages to finance their own campaigns of lies, innuendo and mud slinging.