As proclaimed TheVerge, Lumia 920 successor codenamed Catwalk will use casing materials "not plastic" aluminum. Unlike the previous Lumia series using polycarbonate material.
Although the use of aluminum, called Catwalk will be lighter and thinner than the Lumia 920. Hardware specifications of the Catwalk will match exactly with the Lumia 920, will just different casing material.
A source "familiar" with Nokia's plans said the Lumia "aluminum" will be opening some mobile phones Nokia WP8 which will be launched in 2013.
However, cast aluminum likely only be available in one model Nokia Lumia "Catwalk" only. So not all Lumia 2013 models will use the material "not plastic" is.
If the rumors are true, Nokia seems to want to compete with the iPhone 5, which uses aluminum in the body of the cell phone. In addition, this step is carried Nokia to address user complaints that the Lumia 920 was too heavy and thick.
There is no detailed information about the Lumia Catwalk, including its name, whether Lumia 930 or Lumia 990.