There are a lot of new commands that connect directly to new cards that you would find, like asking "Where's my package?" to get tracking info, or "What's my schedule look like?" to get your Calendar events. Google Now has also added in new prompts when sending emails or texts to help get the message you want to the right place. And, of course there are all of the various new uses of pronouns so you can link together searches to get deeper or related information on a topic.
The tests were done on a Nexus 5 running Android 4.4, but most of the commands are available to anyone on Android 4.1 or higher with the newest version of the Google Search app. There are a lot of things you can do with the app, and it's always good to have a reference for the various commands, because the list is getting pretty big.