I is really funny that when we have some really awesome bitcoin news: like you mention Microsoft acceptance, big hardware online store acceptance or something like that price of bitcoin is not rising at all, and as I recall in these cases it event went down a bit. But from the other side when we can even SLIGHTLY disturbing news: like when that ultra tiny chinese altcoin exchange got hacked last month or so, price of bitcoin went down momentarily. What a pessimistic bunch we are...
But the shit news like Gox, China's endless ban etc directly affected people holding coins right now. Most of the 'good' news is laying foundations for the future, not really doing much in the here and now.
However there's no denying that the market absolutely adores a good panic.