You're definitely right when you say B&W works on a different level. Sometimes I post colour, sometimes B&W, sometimes both together. It all depends on the scene, the image, my mood and what shirt I'm wearing;) The bottom line of course is whether it is a good photograph, regardless of whether it's been shot in colour or B&W.
As to a dedicated thread, why not? I'm game. However, B&W is not your average photographers first choice these days, particularly those photographing the sky. Just don't expect too many contributions, a handful at most!