Noticed this mentioned in MacFormat magazine this month. It is a selection of enhanced Dock launchers for opening different applications such as the iLife or iWork suite. The major advantage presumably is that you can then remove other apps form the Dock to free up space. He also does a Twitter client for iTunes.
Dock is an application that was created to help organize work
environment, maximize efficiency working with Apple's iWork, and to
reduce dock clutter. I built this in a response to my Office Dock