The article about the Challenger mentions a 6.2 Hemi. And the good ol 426 Hemi (is that 6.2L?) was "factory rated" at 425 horse but said to be much closer to 500 in real life.
As for if the new engines are real Hemi's, I don't know much about them. The original Hemi was big back in the day (1950's-1970's) cause it was a radical design, now days hemi chambers and pent roof chambers are pretty common I believe, but the legend of the name sells cars, and that's what DCX is wants afterall.
I kind of like this new Challenger, from what I can see in the 2 pics in that article. I may have to get down to the NAIS this year to see it in person.

Shawn Clone Jezabel- 1999 SE Sport V6 MTX- Severly wounded, comatose Silver frost/Black Exterior-Midnight Blue Interior The Firecracker- 1995 Mystique LS V6 MTX stock and backfiring like a rifle shot I have 3 loves, my God, Brittany, and my Car.