I found this interesting tidbit on allpar: "Challenger is to run through model year 2015 or 2016 with minimal changes, while the new E-EVO platform is developed; the supercharged 6.2 Hemi is now thought to be arriving in 2013 or 2014. After that, Challenger’s fate is unknown." This supports the Ralph Gilles' remark on Autoline that "the Challenger will not become irrelevant."
Allpar is also reporting that the first SRT car to get the new 6.2 Hemi will be the new Barracuda! I wonder how they will price it?