As well as being a great introduction to Scala, "The Feel of Scala" talk [1] by Bill Venners also gives a good insight into the design choices that underpin improved development productivity. He explains how developers can progressively take advantage of functional programming techniques while retaining the advantages of experience gained in Java style object oriented development. Bill also helps you compare and understand the different benefits of Scala, a statically typed language, with dynamic ones such as Python and Ruby.
Links:
[1] http://www.parleys.com/display/PARLEYS/The Feel Of Scala