Have you looked at building a more robust WSUS environment with
downstream servers at appropriate locations to reduce WAN traffic?
Also you need to set a deadline for updates in WSUS to force updates
to install. If you just approve them with no deadline the updates will
install as they are able to, or as the user allows. With a deadline
set the user will be forced to reboot (if a reboot is required) when
the deadline expires. In general Microsoft only sends out updates once
a month, and defaults for Windows clients is to check in with Windows
Update or the configured WSUS server every 22 hours. I'm not seeing
how updating Windows and other Microsoft products more often will
help.

WSUS also uses BITS
(http://en.wikipedia.org/wiki/Background_Intelligent_Transfer_Service)
to transfer data from server to client, so in theory the users
shouldn't notice the download taking place. Not sure you could say the
same thing for BitTorrent.

-- 
Andrew S. Zbikowski | http://andy.zibnet.us
IT Outhouse Blog Thing | http://www.itouthouse.com