Don't get me wrong - I am glad that they included the pivot transform, and I recognize that the dev team likely ran out of time to implement any sort of UI, but Wow! That thing is way more difficult to use than it needs to be.
For instance, and I don't doubt that it is somewhat user error on my part, but in my first attempt to get it working today with 3 columns (UserID, AttributeName, AttributeValue), the transform coughed, choked and wouldn't start. It just gave me errors. Due to lack of time, I had to set it aside for now. I appreciate its usefulness, but it is painful to use, and due to the limited info on the Internet about it (there are roughly 2 useful articles/blog posts), I am guessing that a lot of others just work around it as well. A shame, since the Unpivot transform has a UI and everything.
In summary - I am not saying it is broken, I am not saying it is not useful. Just that it not only is difficult to use, but that documentation and samples are lacking as well. Here are the few useful posts I found:
UPDATE: My friend Matt pointed me to a blog entry that he wrote while at our old company that is a still up in which he gives some tips on the pivot transform.