Power of defaults

Interesting article in the Economist this week about Google, Yahoo!, and MSN's interest in AOL: The battle of the portals. This last bit was surprising:
Ultimately, it all comes down to the three suitors' estimates of what Mr Varian calls "the power of the default". Default users are "the great unwashed", says Mr Varian. They are the ones who, for instance, use MSN because it comes pre-installed in Internet Explorer, the web browser that itself comes pre-installed on new computers...Default users are less demanding, older but nonetheless rich enough to target with small hyperlinked text advertisements. For the dealmakers, it all comes down to figuring out how much these naifs, collectively, are worth.
I think the power of the default is diminishing, but I have no proof to back it up. Firefox, blogging, flickring, and even the rise of Google all indicate people are willing to go beyond what's placed directly in front of them. The teenagers and geeks the article mentions who change defaults don't account for the millions who are changing browsers and publishing online. I'm sure defaults are still an important force, but I think their value is waning.