StudioDaily has an awesome article on how they are using Adobe Premiere Pro CS6 on SNL. They were in Final Cut Pro and decided to move to Premiere Pro, especially because of the workflow with After Effects.
Still I am surprised it is all Mac, but they obviously had Macs for Final Cut. So far I am impressed with CS6, but there have been some stability issues for me, especially with CUDA, though hopefully that last NVIDIA update fixed that. I would think PC’s would be faster and more stable, though I do still love my Mac. They had just better make a really kick ass MacPro really damn soon!