an interesting (th)read.
Kazaa, I hope will be around for a while yet, in my totally unqualified opinion.
But surely with the proliferation of clients, admittedly not all to the FastTrack network, p2p is something that will take a very long time to eradicate.
and to the original post if you want to preview any downloads (avi/mpeg) then try videolan , it works great.
http://www.videolan.org/vlc/download.html
and don't bother with the built-in player