I've updated the Unity article on Wikipedia and need a better reference from the source on the Dash. However, I can't seem to find any sort of official definition of just what exactly what the dash is, anywhere on canonical.com, ubuntu.com, or Mark's blog. What the heck.
To clarify, I'm looking for a post from a source, be it Canonical or a 3rd party but reliable source, that focuses primarily on the Dash. This post comes close, but it's more of an essay on the progress of the work on Dash, rather than an intro/presentation/definition.