This is possible in Tableau 8.1 with a special product key. Please contact your sales rep for more information about getting your product key altered to include this capability.
Limiting the functionality to specific product keys is by no means an attempt by us to get more money--the key will not cost you extra. We wanted to limit the feature so that we could track how our customers are using it and what (If any) bugs still exist in the new feature.
I hope this helps,
Dan - Thanks, I will contact him!