Wow... Speculation, run amok.
I wouldn't be surprised to see forced induction on smaller motors at some point, but I think it's way too early. The 6.4 is already getting better fuel economy than the 6.1 that it supercedes.
Aside from that, the Challenger is already a niche vehicle. Any engine that it has isn't going to make a huge difference in the aggregate CAFE rating.
^^^ What he said. The info about the Pentastar V6 is old news and Dodge coming out with a blown 5.0 seems misguided at best. The writer doesn't seem aware of the 392 release. My guess is this is something from pre-392 announcement.