Comscore stats show Universal/Blended search results in 17% of Google search queries, according to Compete.com that is more than MSN's total search marketshare and almost as much as Yahoo!'s. Certainly a justifiable business case for taking Universal/Blended search more seriously.

"...we observed over 220 million Google searches containing a universal result, out of 1.2 billion searches overall:

   1. 17% of the queries had a universal result
   2. 16% of total Google clicks were sourced from a page where a universal result was present
   3. 14% of paid clicks were sourced from result pages where a universal result was present"
Source: http://www.comscore.com/blog/2008/03/universal_search_a_first_look.html