According to LeftLaneNews, this is what the next Enzo will look like:

Of course, it’s all speculation right now, but we can expect an even more impressive car than the existing Enzo. Performance will be found mainly by using lighter materials throughout the car. The old car weighed almost 1,500kg, which is a lot for a track-focused hypercar. It is speculated that they will drop the current V12 engine, and replace it with a more fuel efficient twin turbo V8. Although the engine wll be smaller, we should see an increase in power. We may even see a road going version of the KERS unit used in its Formula 1 cars. As with all Ferrari’s hypercars, production will be very limited. No more than a couple of hundred units will be produced, so make sure you place your order as soon as possible!

Link to more information: LeftLaneNews