Microsoft has announced that Delve and Officegraph have started rolling out to people. You can read more here:
Take a look at this short video to understand what Delve and Officegraph are and how they can help you.
I’m still waiting for Delve appear on my Office 365 tenants (fingers crossed) but if you want to ensure you opt in to the Preview Features make sure you go to your SharePoint Online Admin Center and select Settings.
From there ensure you have the Preview Features set to Enabled as shown above.
I’ll post a review of my experiences as soon at Delve appears on my tenant. In he meantime, if you have Office 365 check you tenant NOW!