FORTUNE — The announcement just turned up on Apple’s (AAPL) home page. The fine print:
Live Streaming video requires Safari 4 or later on OS X v10.6 or later; Safari on iOS 4.2 or later. Streaming via Apple TV requires second- or third-generation Apple TV with software 5.0.2 or later.
My San Francisco colleague JP Mangalindan will be live blogging from inside the Yerba Buena Center. I’ll be watching from home. You can too.