Microsoft has a private Office 2016 beat group who have access to the next version of Office, and if you feel bummed that you were not included in the group, there is now a way to download the bits.
If you head to the source link below, you can now sign up for the Office 2016 preview and download the bits right now. After signing the NDA, you will be taken to a dashboard where you can download the January technical preview of Office 2016.
During the sign-up process, it will ask you to enter the email address where you received the invitation to join the program but if you enter any email address, you are automatically accepted into the program. We are not sure if this is a bug, as it would appear that they do try to authenticate the email to the user before offering access, or simply a backwards way to reach the open beta, either way, it allows anyone to download the pre-release software.
If you are like us, and don't want to sign the NDA but are still curious about what the build includes, you can check out our gallery here.
[Update] Well the fun is over, Microsoft killed the link that allowed you to sign-up.