The update is specifically meant for those who want to view documents offline. Of course there are other improvements too, such as improving the overall experience for viewing Google Docs on an Android-based tablet.
If you want to view a document in offline mode, you just need to select the document and make it available for viewing offline. Pretty simple, and a feature that many Google Docs for Android users are probably very excited to use. Go ahead and head through the source link to learn more.