Relevant results from your own data now included
You won't have to do anything, but developers of third party apps will. Some are ready, with names like IMDB, Wikipedia and Open Table already displaying relevant results. For these apps, the search result will include an "open in app" button that does exactly what you think it will — open the app with the relevant information ready for you.
In addition, searching for apps will now show relevant results. A search for downhill ski app (Google's example) will show results from Google Play with a handy button to go fetch them.
Google is actively working with developers to get more apps included. If you're a developer and want in on the action, visit here to get started.