A product manager pointed out this product when I was showing her our new MS Analytics (olap) implementation a couple weeks ago.
They have some great examples on their site of just how powerful this product is. http://www.tableausoftware.com/learning/examples
It is spendy, $1500 per named license + maintenance.
It’s primarily designed to go against Excel or table data, but it works with olap cubes as well, or at least somewhat. Just enough to get you excited then you find out there’s a number of things you can’t do. Hopefully this will be enhanced in a future version.
It works outstandingly well if your data is nice and pretty. Normalized well. Of course all of the sample data falls into that category. It also works well against SQL, gain if your joins are easy to do. It would be nice if they had a visual tool for creating joins.
Even so, I highly recommend it.