Why would NBC in this era of instant communications believe that showing its Olympic coverage from Vancouver on tape-delay will work?
In reality, it knows tape-delay won't; and the network is planning for lower-than-expected ratings as a result.
In the "old days" (read the 1960s through most of the 1980s), Olympic broadcasters had a somewhat easy job -- produce an Olympics telecast that suggested the United States was going to (athletic) war with the Soviet Union. Now, the big, bad Commies are gone, and no new "boogieman" has replaced them. (The Iraqis? Come on.)
Moreover, and more germane to this post, the increased presence of instantaneous communications ensures that many, many people will know the results of events long before they will be shown on television. (And the Vancouver organizers are dealing with that already -- bits and pieces of tomorrow night's Opening Ceremonies are starting to filter out through so-called "new media".)
The International Olympic Committee cannot deny this reality, and it certainly is something any television network will need to take into consideration as it bids on the rights to future Games. Do not misunderstand me -- the Olympics brand remains strong, and it is one of the few international sports events that cuts across various viewing demographics. But producing the broadcast is different now.