Some details are coming out about about the possibility of a more powerful 86/FR-S, straight from Toyota themselves.
Chief engineer Tetsuya Tada told Drive, "I hope to make an engine upgrade at least one time with this car."
"We [have] already tried all possibilities and there are several types of 86 prototypes at the Toyota proving ground now; one is a turbocharger, one is bigger displacement and [the other is a] special hybrid system. All possibilities are being considered."
This update will more than likely occur in 2015, when the next-gen 86 is released. And yes, Tada is already working on a concept of this model, which may not include the now famous boxer engine. That could mean that Subaru will be dropping out of the equation, hopefully allowing Toyota and Tada some more creative freedom with the design and specifications.
The seems that the most popular option, at least for Toyota, would be a larger displacement setup, pushing the boxer from 2.0L to 2.6L (which would be equivalent to 254hp). However, the turbo option is not off the table, due to Toyota's recent development of a turbo-charged 4 cylinder for their NX concept which will be shown in November.
As for the hybrid system, I believe that Toyota's super capacitor system will, in some way, shape, or form, end up paired to one of the engines. It's not nearly as heavy as other systems, and could give an even greater power boost (or added fuel economy?) to the new engine.
No matter what engine ends up in this thing, I trust Tada to create something marvelous in the next few years...He clearly didn't disappoint with the first gen 86. Where do you see the 86 going in the next few years? What would make you run out and immediately sell your organs/children...and what would completely ruin it?