This is not port forwarding.
This is setting for incoming connections port (you still have to port forward this port!). If you set it right - you will be able to get more peers while downloading some stuff. Nothing more.
While I was laughing on this crazy idea, i run uTorrent, followed your tutorial, set port to 80, saved, then tried accessing my current external IP 91.150.166.2 via TCP - with no luck
So PLEASE BELIEVE ME - this is not port forwarding. Really. Trust me.