Pretty good, through post on Comscore's updated QSearch 2.0 on Read/WriteWeb by Josh Cantone - comScore Releases qSearch 2.0 - Disproportionately Favors Google.   

"…Over the last two years or so we have seen an increased blurring of what we'd call classic search," said Dennen, who said that this example shows how web 2.0 is influencing and changing our attitude toward search."

"…Web seaches that originate from third party sites are now counted by qSearch 2.0. For example, if you visit the CNN.com site, and perform a Google web search, that search is now counted in the qSearch metrics. Only web searches are counted, however. Google-powered searches of CNN.com, for example, would not be counted. This change benefits Google the most, according to comScore, who have, at least anecdotally, had a much greater success rate in getting third party sites to install their affiliate search engine than their competitors. Google experienced the largest jump in search share among the top 5 when comparing qSearch 2.0 data to qSearch 1.0 data for June 2007.

To me, the more interesting part is including Social Networks and searches across verticals in QSearch Traffic:

"…qSearch 2.0, because of a greatly expanded data set, also now has the ability to measure verticals separately and more accurately. comScore plans to expand their measurement offerings to verticals such as jobs, travel, and retail searches. qSearch 2.0 also measures what comScore calls "multi-tab" searches as separate queries. This means that if someone performs a web search, and then clicks on the "Images" or "News" tabs, those are considered separate searches by qSearch 2.0, whereas they had been considered one search with multiple results pages in the past. The reason for this is two-fold, according to Dennen, first that consumer intent is different for each search, and second that monetization is different for each of those verticals. This change also disproportionately favors Google."

So if you have "tabs" on your portal for different categories of searches (ie: like "news" vs. "trends" vs. "image search" each will count as an individual search whereas before they'd count as one search (if you started on one and went to the another tab, that is).

But I don't see why that favors Google more, since Yahoo has the same thing… but maybe Yahoo doesen't get as much Search Traffic as Google so any differences that benefit Google are magnified.

"..Perhaps the biggest change, however, in qSearch 2.0 is their expanded data set. qSearch reporting now includes the top 50 sites world wide where search activity occurs. This includes MySpace, YouTube, Baidu, eBay, Craigslist and a host of others, in addition to major search-specific properties. qSearch 2.0 is also expanding their international sample size. In the past, qSearch only measured data from the US, UK, Germany, Canada, and France (as well as aggregate data from the rest of the world). Version 2.0 now measures China, Japan, Korea, and Mexico, with Italy, Spain, and Brazil coming next month. India, the Netherlands, Russia, and Argentina are scheduled for inclusion in September.