Add a link to the apps I/O presentation from the docs.

chrome/common/extensions/docs/static/about_apps.html

 <meta name="doc-family" content="apps">
 <div id="pageData-name" class="pageData">What Are Packaged Apps?</div>
 <div id="pageData-showTOC" class="pageData">true</div>
 
 <p>
 Packaged apps deliver an experience as capable as a native app,
 but as safe as a web page.
 Just like web apps,
 packaged apps are written in HTML5, JavaScript, and CSS.
 But packaged apps look and behave like native apps,
 and they have native-like capabilities
 that are much more powerful than those available to web apps.
 </p>
 
 <p>
-<iframe title="YouTube video player" width="610" height="380" src="http://www.youtube.com/embed/lBUGTVIJVfM" frameborder="0" allowfullscreen></iframe>
+<iframe title="YouTube video player" width="610" height="380" src="http://www.youtube.com/embed/lBUGTVIJVfM" frameborder="0" allowfullscreen></iframe><br>
 </p>
 
 <p>
-With access to Chrome APIs and services
-not available to traditional web apps,
-you can build powerful apps that interact
-with network and hardware devices,
-as well as, media apps.
-Here's a short list of examples:
+Packaged apps have have access to Chrome APIs and services not available to
+traditional web sites. You can build powerful apps that interact with network
+and hardware devices, media tools, and much more. Here's a short list of
+examples:
 </p>
 
 <ul>
         <li>Shells (VMWare, Citrix, SSH, RDP or VNC clients)</li>
         <li>Music/video streaming</li>
         <li>Photo/video/music editing</li>
 </ul>
 
+<p>
+Watch the <a href="http://www.youtube.com/watch?v=j8oFAr1YR-0">Chrome Apps
+Google I/O presentation</a> for an in-depth introduction.
+</p>
+
 <h2 id="look">How they look</h2>
 
 <p>
 When a user opens a packaged app,
 their focus is specifically on the tasks
 relating to the app.
 Packaged apps have no traditional chrome:
 the omnibox (address bar), tab strip,
 and other browser interface elements no longer appear.
 Like native apps, they don’t live within the browser.
@@ skipping 62 matching lines @@
                 and how to connect your app to other apps using web intents.
         </li>
         <li>
                 <a href="app_deprecated.html">Disabled Features</a>
                 describes the web features that have been disabled
                 and what to use in their place, where relevant.
         </li>
 </ul>
 
 <p class="backtotop"><a href="#top">Back to top</a></p>