Awesome

2D Shadow & Visibility

2D Visibility / Shadow casting converted to Unity C#

(coming soon)

Original sources

http://ncase.me/sight-and-light/

Related Unity forum topic

http://forum.unity3d.com/threads/165283-2D-Dynamic-Shadows

More info & Webplayer demo

http://unitycoder.com/blog/2014/10/12/2d-visibility-shadow-for-unity-indie/