It will make use of the New Nintendo 3DS' unique capabilities.
Brian Provinciano from Vblank has given us a tease for the upcoming Retro City Rampage: DX update. On Miiverse, he talked about notable functionality changes, and particularly for the New Nintendo 3DS.
The game will now run at a solid 60fps on all systems, there is a new Spanish translation, and you will be able to to turn cops coins on or off. On the New Nintendo 3DS, you will be able to use the C-Stick for more options during gameplay. The New 3DS' CPU hasn't gone unnoticed either, as the system allows for a smoother turbo mode, better screen effects, and faster forwarding. Brian plans to provide more details very soon.
Retro City Rampage: DX has been available on the 3DS eShop in both Europe and North America for more than a year now.