The Red Hat ImageMagick RPMs always seem to be a couple of patch versions behind the Latest and Greatest (5.2.5 vs. 5.2.7) anyhow. I've been using ImageMagick for several years now and it's a software package that's worth keeping up to date on. In particular, the command line stuff really rocks. If you can make sure the newer ImageMagick binaries land on top of the old stuff, you shouldn't need to diddle with Tcl regexp in the ACS/OpenACS.
The big Linux distributions seemed to be heavily focused on the GUI tools (e.g., The GIMP, Electric Eyes, xv) and tend to ignore the command line stuff. Even a marketing moron like me can write a shell script that will convert the contents of a Master PhotoCD to 1.8 GB of TIFF files in a matter of minutes using the ImageMagick convert command.