The SRT engineers stated here in a chat session that the factory designed service life of the Charger is 250K miles.
That said, it's just a collection of parts and with proper maintanence and parts replacement, it can last indefinitely.
Many cars have gone well over 1,000,000 miles and are still going strong...
"Some car manufacturers support a "high mileage" club. For example, Mercedes-Benz has a "High Mileage Award" program in which owners who drive 250,000, 500,000, 750,000, and 1 million kilometers are awarded with a certificate and a radiator grille badge.
Many non-commercial vehicles (both auto and truck) have exceeded one million miles. For instance, in 2011, Irv Gordon had accumulated 2.9 million miles in his 1966 Volvo P1800. In 2006, a 1995 Dodge Ram was reported to Chrysler as having gone 1 million miles.
A very long running car is a 1976 Mercedes-Benz 240D in Greece of Gregorios Sachinidis that has reached 2,858,307 miles before retiring to a Mercedes-Benz museum in Germany.
Another was the 1963 Volkswagen Beetle belonging to Albert Klein of Pasadena, California that had racked up to 1,442,044 miles on 25 Jan 1993.
AARP Magazine featured several long-running cars (over 200K miles) in its July 2009 Issue."