The term 'All-New' can be tossed around a little loosely in the automotive industry but this was a true clean sheet design. Instead of taking the design from the old Civic and adding some new minor details Honda took the approach to take what made a Civic great over the years and designed it from the ground up to exceed those older models.
One of the major design points was to bring the sportiness back into the design that was getting diluted over the iterations of the Civic. The design is low slung and more aggressive with the wheels pushed more towards the corners. It's 1.2 inches wider and 2 inches wider than the outgoing model. This also adds to more space in the interior. The rear has the appearance of a Fastback yet has a conventional trunk. The front fascia has a more aggressive look to it as well.
The Civic introduces some new power plants including a 174 hp 1.5L DOHC Turbo on the Touring trim. To see how powerful it is check this video out between the new Civic and the old Civic Si: