New cuda ?

Dodge trademarked the Cuda name in 2010. Alpha Romeo based car, similar platform development by Chrysler and Fiat will be released under the SRT name, along with the Viper.

Why would Chrysler need something to compete with Challenger?

It will replace the Challenger, completely, for 2015.

http://www.amcarguide.com/muscle-cars/cuda-is-to-change-challenger/