Reproduced on 4.2.0a4

1) What happened
Using a surface shader with a worldNormal calculated and set to the surface normal, combined with deferred rendering works correctly on ATI cards. However on NVIDIA hardware the lighting isn't effecting the shader.

In forward rendering the lighting does not effect the shader on ATI cards as well.

2) How can we reproduce it using the example you attached.
Open the scene under NormalDeferredBug/normal_deferred_bug.unity

Play the scene on an ATI card and notice the cloth is bright. On NVIDIA hardware the cloth is unaffected by any kind of light