I've lost count of the number of times people have asked for asynchronous segments in the Pipeline distribution. The problem was always coming up with a simple enough API for it.
Another thing I've wanted to do for a while was to seperate the act of dispatching the segments of the pipeline from the pipeline itself. This was a fairly simple one to do, but until I had an API for asynchronous segments there was no really compelling reason to do it.
So anyway, they are now both done. I need to spend some time on the code base refactoring the various bits and pieces that have been added, and I want the asynchronous segments to work independently of ithreads (and thats not too hard as it turns out), and then it will make its way on to the CPAN.
edit: asynchronous, even