Apple has not come out and said a firm no to it, but it looks and sounds like there is not going to be a web stream. However there is a Satellite feed. And MacRumors just posted a list of Apple Stores that will be showing the feed.
I will put it this way, why would anyone go to the Keynote if it was broadcasted public? I don't think there will be a WWDC keynote broadcast till after the fact, and I presume it will be via the web and not via the Sats.