In an interview at the Web 2.0 conference, Googel CEO Eric Schmidt mentioned that Google would like users to be able to have portability with their search history data:
Schmidt said he would like users to be able to export their search histories between different search engines. “We want to give you essentially the equivalent of number portability,” he said.
Google respects the rights of its users foremost, Schmidt said. “As long as we don’t do something against their interests, we should be fine,” he said. “The more that we can, for example, let people move their data around…and not trap it,” the better.
If true (and if ever achieved), this would be a significant step towards giving users more control over their data that is collected by search engines.
UPDATE: In the comments below and on his own blog, Seth Finkelstein is much more skepitcal of Google’s intentions:
While at face value, this is a praiseworthy statement, I am more cynical. Institutionally, Google is known for
1) A prodigious appetite for data 2) A maniacal secrecy 3) Good PR
Putting this all together, I don’t think he wants to make it easy for users to move personal data away from Google. I think he wants to make it easy for users to move personal data away from Microsoft and Yahoo to Google. I suspect this is in fact an attack aimed at Microsoft, where he’s going to wave the banner of “portability” against possible Microsoft operating system lock-in tactics.
Not that there’s anything wrong with that.
But it’s about Microsoft and what Google perceives as competitive advantage, not about “the choice of the users”.
MichaelZimmer.org 
While those are his literal words, I see no reason to take them at face value.
I suggest it makes more sense to look at the opposite implications:
“We’d like to be able to get your search history data from Microsoft, rather than have them build a wall with Vista that keeps us out”
You’re probably right; I must’ve been in an optimistic mood last night.. š