Usually, the keynotes are put on the interweb a few hours after it's done.
then, the servers slow down to a crawl as millions of Mac-nerds all try to watch it at the same time.
(go use the Apple store computer. Their connection is usually faster than my in-home anyway)
And I just wander on down to the internet café at about 3pm and get a perfect stream cause the majority of the world's Mac Addicts have gone off to the land of Nod.
Mind you, the keynote is at 4am my time - damn daylight saving.