Brad Abrams was kind enough to correct me on my former post on PowerCollections. He says they will incorporate the best collections into the BCL after they've gone through the community process. This reminds me of how the STL rose up through the ranks because of it's merit rather than the original C++ class library and was much more successful because of it. I'm sure the similarities are not coincidental. It's an even better parallel to the Boost library.
This is tremendous news not shared in the post.