The online advertising prophecy

Today The Wall Street Journal has an interesting (and free!) column by Robert Guth about the new media industry. He talks about the hypes and lows of what we once used to call the New Economy. Basically he says that opportunities come and go extremely fast. Only the best survive and sometimes not even them.
For what concerns Internet advertising, undoubtedly big brands budgets are heading online. However we need to keep in mind they are “moving” from other sectors (Tv, radio, print), it’s not that more money is being invested in promotions through the Internet and, “if the advertising budgets shrink, the online guys will likely get hit just as hard as any of the traditional media outlets“.
Is this a prophecy or just a cautious warning?