elementary-style headerbar icons in Pantheon
At GUADEC we discussed introducing some elementary OS/Pantheon specific UI tweaks so that we don't have to carry downstream patches. It sounded like checking the XDG_CURRENT_DESKTOP would be the best way forward so that it was checked at runtime instead of compile time.
The first of these tweaks is setting the headerbar icons to be full color and toolbar-size when running under Pantheon.