Diablo III is announced in Paris
Blizzard officially announced Diablo III on June 28, 2008 at its Worldwide Invitational in Paris, ending eight years of rumors with a cinematic reveal and live gameplay.
Source: GameSpot — 'Diablo III ignites Blizzard Paris event' (published June 28, 2008); Diablo Wiki — 'officially announced on June 28, 2008 at the Blizzard Worldwide Invitational in Paris'