Just came across this article today...nothing extraordinary, but maybe a few details:
Nissan Has a New 500-Horsepower Z Concept Coming
Also, earlier in this thread folks were discussing that Mazda has given up on sports cars. This might be in the works:
Gorgeous Mazda RX Vision on track for 2020 | Top Gear At a recent visit to my Mazda service department, there was even a slick article in their Mazda magazine about it with an interview. This article is posted on Mazda's official website.