They have made some changes such as relocating the exaust ports to the rotary chamber side housing also where the intake ports are located which eliminates the timing overlap of intake and exaust ports giving the engine more stable combustion and better fuel economy.
The renesis rotary engine is still the 1.3L 2 rotor in-line engine that has two sections each containing a rotor. Then there is an eccentric shaft ( like a crankshaft in a piston engine) which sits 180 degrees out of phase putting the power to a flywheel.

The intake and exaust ports are larger than any naturally aspriated rotary engine by 30%. This reduceds intake flow resistance also improving fuel efficency and reducing emissions.

Its the same 13b that they have been making changes to for many years.
This time they are calling it the Renesis which is 30% lighter and 20% smaller than before.
Basically they have made some major inprovements.
-Leaner fuel mixture
-increased combustion efficiency and fuel economy
-reduced emissions
40% less fuel consumption at idle than the rx7