Sadly, the past tense above is no accident. Techspansion's website has been shuttered and the products have been discontinued. Tyler Loch (Techspansion's founder) let us know that the difficult decision to close down Techspansion is a personal one, and he's readjusting his priorities to focus on other needs. His choice is understandable, but we will definitely miss VisualHub (not to mention the laugh-out-loud funniest release notes in software history). Best of luck to Tyler in his future efforts.
Update: For those who are inquiring, there are no current plans to move VisualHub to open source. The underlying engine for much of the compression magic, ffmpeg, is already open-source and present in other Mac tools such as Handbrake.