I think that the styling on the 2015 'Stang is great. Some people have said that the back of the car looks like a Honda Accord, but I personally don't see that. The front of the car has a more aggressive profile, and it looks (visually, at least) like it's a bit more aerodynamic than the last few years of Mustangs, and most likely more than the 2005-2010 Stangs, in which Ford had admitted that aerodynamics took a back seat to visual appeal (especially the grille/ front area). The sides appear to be a little narrower than in previous years. As a '99 Mustang owner, i'm more of a fan of the '99-'04's, in which I think it's a good blend of modern and retro.
There's some good points in this thread. The turbo'd 4 cylinder sounds like a great idea in theory, and the power numbers are phenomenal. But are the slightly better numbers than the V6 and the slightly better gas mileage worth it to enough people to make it viable for Ford? As we've seen on the SC's and Turbo Coupes, when people don't maintain the cars well, the motors take a beating. And this being a new engine, the R&D only goes so far....the ongoing R&D becomes anyone who buys it and drives it under various conditions. As it stands, the Coyote 5.0 suffered and is suffering from some piston #8 failures, and with the horsepower wars between the Camaro, Challenger and Mustang, when power numbers are boosted, obviously, the question becomes how long that the motors will last. People always want reliability, economy and power, but very rarely do those go hand in hand, especially when you really start putting some serious mileage on a motor.