World Of Warcraft: Concerns of Background Downloader

Some concern has been raised regarding the background downloader. Is it helping or is it hurting World of Warcraft?

NOW with it running in the background, all I would have to do is figure out how to send some bad data down the wire to any computer on the network (and since it is a peer-to-peer network, I can get the list of addresses on it) that would hijack the downloader, package my little virus or spyware, or better yet an application that read your account name and or password right out of memory since the game is currently loaded and send it back to a centralized server.