Apple's WWDC '14 keynote starts in less than an hour and you can watch the whole thing live as it unfolds. The catch is you need a compatible Apple device.
The WWDC live stream is available to anyone using OS X 10.6 or later with Safari or iOS 4.2 or later, again on a Safari browser.
Naturally, the Apple TV owners will be able to enjoy the keynote too, they need a second or third generation Apple TV with OS v5.0.2 or later.
You can watch the WWDC live stream here.
Alternatively, you can try this stream that should be available to everyone.