It is not the Evos. One of their graphic artists just photoshopped a few changes on the current design. The '09 to '10 changes were far more comprehensive than what they are showing for the '14 to '15. One humorous change in one of their pics is they added a fourth "bar" to the tail lights. There is only so much they can do for the mag though. The pic with the four bar tail lights also has a different quarter window and more of a true "fastback" design (along with no cut lines for the trunk lid...).
Not bad not great, I'll keep my 12. Don't know why they hyping the 2015, I would think they would want to try to get the 50th anniv in 2014 advertising going, but I guess after the annv they feel the need for a new look to enter the next 10 year period
The '15 Mustang will probably go on sale in April 2014 like the '65 did in '64. The new model will have a longer sales year. That will make the '15 model also the 50th anniversary model, thus the hype for the '15.