I'd like to see where it's confirmed there will be a turbo. All I see now are rumors. There has never been a secret that a turbo FA20 is being built, it already exists in Japan. But the big question was whether it would be put under the BRZ's hood. As far as I know, that hasn't been confirmed.
"Inside Sources" is just journalism-speak for "Shit I just thought up". According to "inside sources" the 2008 STI was supposed to be a 3-door hatch with 350hp. Nothing's confirmed until Subaru comes out and says it, or it's sitting on a plinth at the Tokyo Auto Show.
Now, that said, I hope they come out with a forced induction version. This car is VERY fun to drive, and giving it more power till entice more people to give it a try. If anything, when other competitors hit the market it'll help them keep a step ahead.