It made news because those in the news interpreted the statement the way they wanted. Palin, in the debates, was much more cogent on the role and showed a pretty clear understanding.
As for the actual role, Pres Senate, while having no vote, presided over and had very strong governance of the Senate rules and often did guide the debate. Now whether you consider that "in charge" or not is largely based on your own interpretation. In general terms, having the title President is interpreted in simple (3rd grader) terms...as in charge. In more recent times that role has been diminished. Who is to say that, if they had been elected, that she would not have spend more time presiding over the senate, if for nothing else just to piss off Nancy Pelosi?
Personally, I treat this story the same way I treat the "mission from God" controversy. The second being taken from a speech she made IN A CHURCH to a bunch of guys waiting to become priests. When you are starting from the belief that she's an idiot, this will simply confirm your belief. This is the same reason the "Africa" scam got so much traction.