Google today is releasing new search infrastructure to combine its video, local, book, and images search systems with its text search. Marissa Mayer is describing the new system as I type, but basically it will lead to much more relevant search results.

As an example, searching for the "I Have a Dream" speech will return a Google Video clip of the speech itself, just below the text of the speech.

Google is also adding contextual navigation links (like Ask.com) to let users drill down to a particular type of information like "books" or "blogs."