A P2P protocol like BitTorrent saves bandwidth on servers distributing to many clients. It does not save anything on clients. Think about it: each client is still receiving the same amount of data - more, actually, because of the additional overhead involved in P2P.
So WUDO helps Microsoft save bandwidth, but it has little or no benefit for users if they leave the "PCs on the Internet" option checked. If WUDO limited to PCs on an internal network works as it should (you'd have to trust Microsoft on that one), it could be helpful, but remember that it bypasses any internal controls or checks.
P2P is inherently not very secure, even if the proprietary BitTorrent protocol has no known vulnerabilities . I don't know of any security conscious organization that allows BitTorrent or similar P2P systems to distribute internally anything that comes from outside sources directly.
The proper way to redistribute software internally - and the way any responsible administrator does it - is to download a redistributable to one system, check it, and then redistribute it. Microsoft provides this capability for nearly everything you can get from their site. Just look for the IT and tech support versions.