BTW, I think people have forgotten what a "liberal" looks like if Olbermann is held up as the extreme of the left wing. Remember, America is in the middle of recovering from one of the most severe ideological swings in recent memory, and so things that previously were center or even slightly right-wing are now seen as being extremely liberal. For instance, Obama's health plan is extremely similar to that proposed by the Republicans in the mid 1990s. Point being, bias can be seen relative to the zeitgeist, from which view MSNBC etc can be seen to attempt to steer conversation rightwards by making issues such as "deficit reduction" more discussed than issues such as "unemployment." Olbermann and Maddow spend much of their time defending their own views, and rarely set the tone of the conversation.
It also bears mentioning that the status quo before Obama's health care plan was, for the most part, proposed and enacted by leftist Democrats over the past several decades, and the maintenance of those systems has been seen as right-wing or centrist when their creation in the first place came from the left. The few actual right-wing reforms to health care (such as the HSA) are in fact weakened by Obama's reforms.