f12 yum/rpm commands to list all dependencies on a library

[Skunk Worx]

On f12 I see a package called oprofile-gui depends on the qt3-3.8b rpm.

What command(s) can I run inside a local repo (where all the rpm 
packages are) that will tell me how many f12 "Everything" packages are 
still using qt3?

What command(s) can I run for the locally installed package set that 
will tell me how many packages are still using qt3?

I have a project that I am porting to x86_64/qt4 and would prefer not to 
mix the two subsystems on my development machine.

The /etc/profile.d/qt* files are currently pointing the default QTDIR, 
QTINC, QTLIB, and PATH variables at qt-3.3 locations even though I've 
installed qt-devel which is qt-4.5.

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John