Imaginesim have released a Prepar3Dv2 version of their current KATL Atlanta USA as part of their reduced priced legacy range.
This will be a stop-gap solution for your flight plans because a completely new-build KATL Atlanta under development will be released in 2015 to the high standards set with their last two releases, ZSPD Shanghai and KAUS Austin. If you have already purchased the FSX version of KATL then you get the Prepar3D version for free (see website for details).
There is a demo version to sample and screenshots over at www.imaginesim.com.