I view the media as only ONE (among many) of the "Checks and Balances" we have.
With that said; it's importance has become lessened by it's ever increasing bias and lack of balanced reporting.
Now; one could argue that this lack of balance and the bias that they have is a reflection of "our" (society as a whole); and 1) our desire for the sensational, superficial and 2) (as someone mentioned) our desire to not necessarily know "truth"; but to hear only from those sources that agree with us and feed our biases.
So...in answer to your original question, Teco:
Media COULD be one (among many) Watchdogs of Democracy...but it's value is diminishing on what seems like a daily basis.