I am using Unity for my next project due to the need for a web player. I wouldn't say 3DGS is dead though, it does many things right. But it also lacks in key areas(multiplatform, art pipeline, performance). As Frank said, if your planning on doing something more basic for windows use 3DGS. I do miss Lite-C with Unity too, I still think 3DGS had the best scripting system.