The Mint team deserves big kudos for striving to maintain a Gnome-panel-like desktop experience. IMO both Gnome-shell and Unity are arrogant usability nightmares; thankfully the Mint team is still keeping traditional usability alive in the Gnome environment.
The bigger point here appears to be the extensibility of GNOME shell. If I read the announcement right, the Mint desktop is GNOME3, but using extensions to create a more GNOME2-like experience.
The JavaScript environment GNOME3 was written in could lead to lots of UX experimentation like this, at least once it has better documentation.
