Whatever the reasoning, Google has a short video that will walk you through some of the Google Apps available on the Nexus 7. The video covers Google Earth, Gmail, Maps, YouTube, and the Chrome browser. Each app only gets a short time, so this is really just a primer for newbies, but it's a good video nonetheless. And, even though the video doesn't go into it, you can definitely see that the Google Apps folder on the Nexus also includes Google+, Currents, and Talk.
We're going to assume that Google has at least one more of these videos coming soon which will be a walkthrough of the Google Play Store itself. That would round out the beginners guide. After that, it would be a matter of whether or not Google wants to get into more in-depth how-to videos for Android.
source: Google Nexus YouTube