The production version of high-performance BRZ STI began to be revealed on the official Japanese STI web page, meaning we might have an official reveal in a few months. They even say "Coming Soon". The obvious choice would be to think it will be shown at the Frankfurt Motor Show but is more likely to be revealed in November at the Los Angeles Auto Show.
The obvious things that we know about this car is that it will have a more aggressive body kit, that includes bigger wheels a rather large rear wing. There will be, of course, a power increase that won't be obtained with a turbo because it seem the engine bay doesn't have room for the intercooler. Reports suggest it will have around 230PS (227bhp or 169kW).