Vox Media is the parent umbrella company that SB Nation and its sites fall under, as well as tech site The Verge. Work on the SB Nation redesign has largely been down to the webheads working on Polygon, and now SBNation United is up and running, work went into launching Polygon as its own individual site (it had previously hosted its content as a sub section on The Verge).
Polygon aims to be a big deal among the videogame website properties already out there, and garnered some big story interest on its launch, including a feature article in Forbes
So for all the fellow gamers out there, be it Windows PC, IOS Mac, Playstation, Xbox or Wii, you can check out www.Polygon.com now. I was able to sign in using my SB Nation username details, so presumably you can as well, though options for connecting through Facebook and Twitter are also available.