Yeah unless you're a 1337 Gentoo geek, you don't want to be wasting your life away (okay just your CPU cycles) compiling any of the large software suites out there, i.e. KDE, GNOME, XF86, etc.
Btw, this isn't so much a problem with RPM as it is a problem with Red Hat Linux. Ideally, their up2date service would regularly offer software updates (such as KDE minor version upgrades) in a timely manner. Now I haven't used up2date but I experience the same problem with SuSE's YaST Online Update (except that in my view, YOU is junk). In general, each of the vendors has a strict "no new software, only critical updates" in old stable trees philosophy (some more than others) but arguably sometimes they should allow the consumer to relax this restriction without jumping through hoops.
The alternative forces end users to become more skilled Linux sysadmins, manually upgrading software packages. And while RPM does do full dependency checking, it doesn't really do dependency resolution. So we're stuck trying to figure out exactly what packages are missing and where to get them.
That's why in this example, downloading the *whole* KDE tree and doing a Freshen usually provides successful results without much user intervention. For future reference, I would suggest:
rpm --help