They have got into the search wars !!
"The search utility itself indexes Office documents such as Word, Excel, and PowerPoint, and e-mail clients Outlook and Outlook Express. One rather sweet feature is the utility's indexing of the browser cache; now finding pages you have visited in the past is extremely fast and easy, but currently only Internet Explorer is supported for this feature. "
via : source , Google Details , chatter ; here... but requires certain h/w conditions !1