The most notable change that landed with the update isn’t actually intentional. The black paper displayed in the trash icon when ready to empty is not the result of Canonical inverting their ink and paper but rather down to a pesky bug (LP #702423; thanks Dan).
Various parts of Ubuntu One have been dipped in their new styling: -
You’ll never get your terminals muddled up thanks to colouring differences for ‘root terminal’ and regular bog standard ‘terminal’
The ‘file manager’ icon has been updated to look, well, rather like an actual ‘file manager’. Not sold on it personally but there are only so many ways you can symbolise file management.
Talking of File Managers, Nautilus’ navigation icons look all the better thanks to finer lines: