I have yet to write the third part in the series on writing ip agnostic apps, but in the meantime, Anthony Jones (Winsock Developer/Guru) and I chatted with Charles about the topic on Channel 9: http://channel9.msdn.com/Showpost.aspx?postid=265664

 We had a great time creating the video.  It jumps around to many topics, but I suppose that is what we get when Charles stops by, says hi while powering on his camera and then hits record :)