Source lists are a fundamental part of Mac OS X applications.
They're used in many applications such as:
One important thing to note is that when the toolbar is hidden, the source list should look the same. For example, the top of the source list looks the same in both Finder and Linkinus.
The application developers seem to have missed that here:
I just wanted to follow up with this, while looking at the source for this article I update to the latest alpha release. The alpha release features this:
To quote a friend,
other than the tabs
that is a massive improvement
the tabs are horrific though