Toyota and Scion are the same company. The Subaru BRZ is the same car--this was a twin Toyota/Subaru project. Love these cars. If one of these comes out with forced induction, it may be the excuse to sell the MINI, which is giving me a headache recently, it'd be down to this or an Exige. Rumors of an STI version of the Subaru abound (it's coming, but the question is with how much power), and know one is sure what plans, if any TRD has for the Scion.
I think Toyota has gone on record saying there will not be a more powerful version of the FR-S offered.
They have, but then TRD hinted that something may be in the works. No one really knows for sure, but yeah, you're right, if I was betting, I'd bet on Subaru doing something rather than Toyota.
I was a little suspicious as well, since TRD offers a supercharger kit for the TC. Everyone loves turbos (as do I), but a supercharged FR-S might be very interesting.