MSN and Yahoo! first implemented the principles of a single page that provided a variety of search results on their mobile search products. Google has done this to a limited extent for a while now. Today, though, they have more or less tried to launch the concept of a universal search results page.
Google’s Official blog post about Universal Search explains the problems they had with implementing a universal search results function based on intent detection via a short user-entered query.
The end result currently looks more like a cosmetic change than a significant change in the way results are delivered. Users now get image results, news results, related searches – not very different than before – the only change being that not only do users still see the regular options for Images, Video, News, Maps etc on the top left (no longer just above the search box), but they also get a second navigation bar above the results, with links to the most relevant associated searches.