Yes, it's possible to do this.
It's fairly easy to do, doesn't require any weird mappings or software downloads, and best of all, it's not that hard.
http://blogs.technet.com/b/sus/archive/2008/05/19/wsus-how-to-change-the-location-where-wsus-stores-updates-locally.aspx
Yes, you absolutely can use a UNC path for destination of data.
But .. you have one more step after the location is moved:
Go to IIS Manager
Your server,
WSUS Administrator
Content
Basic settings (on the right)
(See? The physical path is now the new UNC path but ...)
Test Settings
If you have green checks for both Authentication and Authorization, you're done.
If not, close this
Click Connect as ...
Change to (*) Specific user
Set the domain\username
password
password
and test again. If both checks are now green, you're done. If not, figure out the credentials needed to connect to the UNC path. The only downside I've seen so far is that you *must* connect with a domain login.
Your results may vary. Don't blindly trust things on the Internet from people you don't know. If you don't like this, don't do it :).
