Ryan, this has NOT been implemented yet. Feel free to vote up the Idea referenced further down in that thread.
This isn't a feature yet. I think I heard it announced that they are looking into it but I could be wrong. Here are a couple of links that might help depending on what you are trying to do.
The link above contains the links below. Just posting them for your reference.
The second link offers two different methods. One by padding the datasource. One by intense use of Table Calculations which isn't a trivial task. Here is a blog post that covers padding the datasource in a bit more detail:
If you post a packaged workbook with what you're trying to do I'll give one of the above methods a try.