Fit is very similar to Lunar Racer 3. Same platform but a much better upper (seamless). The midsole lunar foam is slightly more dense and extra material has been added to the outsole to increase durability.
Now available at Nike.com in 5 different colors
http://store.nike.com/us/en_us/pd/lunartempo-running-shoe/pid-10199532/pgid-10076953