Normally, WWDC would not generate a lot of buzz in the typical news cycle. Usually there is no new hardware announcement. It is a showcase of new software that will come to users in the next 3 months. But for Apple, WWDC is arguably the most important event for Apple, possibly only next to a new iPhone launch (which now the novelty has weaned off). Millions of people might buy a new MacBook Air or the new iPhone, but billions will use the new software to update the Apple showcase in WWDC.
WorldWide Developers Conference is an Apple event primarily directed at developers that work on Apple’s platform. It’s an event for Apple to showcase and market its upcoming features, their software direction for the next 12 months and also a place where Apple developers can talk directly with Apple engineers itself on how best to use Apple APIs. Traditionally it is held in the early June every year, at the midpoint of Apple events.