Grand Central Dispatch internals and FreeBSD port [pdf]

pg: the scribd link doesn't properly encode this URL and thus breaks. The correct URL is:

http://www.scribd.com/vacuum?url=http://wiki.freebsd.org/200...

I am curious what the answers to the questions on page 33 will be. I am quite curious what open source operating systems add to optimize for parallel (this, something else, or nothing).