Thought I might share this, it is VERY early on script but it works for a lot of things (Phong, VRayMtl, VRayMtl2Sided, VRayLightMtl, Blinn, Lambert). I'm not sure I have the time to maintain this but it might be useful for someone to start.
There ARE bugs. :)
Execute it by using "maya2Corona" (without quotes) command