You cannot be serious. The day Linux makes me look for some obscure setting under {079ACDF2-9218-45CC-B735-AF459E25BC67}\00 is the day I give up on computers.
Not too many settings are stored under GUIDs. Most of the useful stuff would be under something like SOFTWARE/Vendor/Product, just like it would be under /etc.
However, I DO strongly agree that all configuration files should be stored in a single directory. Some are directly under /etc, some under sub directories of that, and sub directories of something else.
That's true for system level stuff. User-specific config would go in ~/.vendor/product.
I'm on FC1 and without the locate command, I don't think I would have found up2date's sources file without wasting 30 minutes looking.
How about:
rpm -qf `which up2date`
and then:
rpm -ql packagename
replacing packagename with the result from the first query.
RPM is a package database that keeps track of files installed on the system, organized by package. The first query asks what package owns the binary up2date, and the second asks what files belong to that package.