For those having issues with the 4.0.1 patch downloading and installing iv gathered a bunch of non-blizz links to threads for you to watch incase problem gets solved. check back here every hour or so cos il post fixes that i find :D
Slow p2p transfer rate, (iv had 15kbps for more than 3 days):
Turn peer to peer trasfer OFF in the downloader preferences, your will then only download from the blizzard direct dowload site.
Friend just told me that if its saying ''you are behind firewall'' close the downloader (all downloaded files are not deleted) and open the wow launcher, not the wow exe, (its in your wow folder). this has solved his problem. hes says the behind firewall massege comes back after a while but he repeats the process.
MAC - http://answers.yahoo.com/question/index?qid=20091208110236AAYlayf