I had no idea my little question/thread turned into all of this.
Just my $.02, I am very pleased with some of the renderings (yes, they're just artist concepts), but that last one (based on the spy-photo) does look to have a well thought-out basis to it. I really like the new look, and am very pleased to read that the next Mustang will be smaller and lighter.
I have spent more time sitting in a deck chair in my buddie's drive way swigging beers, while we admired our freshly washed & waxed Mustang and Camaro, opining that both of our cars were waaaay too big and heavy. I have been hoping that the next Mustang would take a positive stop in the size and weight departments. If the car is around 300 lbs lighter, smaller in size, with 50 more BHP, and an IRS, it will have killer performance.
As far as looking more Euro, more modern, I like it. The retro design theme has been great for almost ten years now. Time for something different.