I noticed that 'utterramblings' is mentioned as a repo on in the Centos wiki, so I decided to risk using it to update pcre.
I did this (based on the settings for configuring the dag repo):
/sbin/e-smith/db yum_repositories set utterramblings repository \
Name 'UtterRamblings' \
BaseURL 'http://www.jasonlitka.com/media/EL$releasever/$basearch/' \
EnableGroups no \
GPGCheck yes \
GPGKey http://www.jasonlitka.com/media/RPM-GPG-KEY-jlitka \
Visible no \
IncludePkgs pcre \
status enabled
repo setup command modified per note from gregswallow below
Then I did this:
signal-event yum-modify
yum --enablerepo=utterramblings update pcre
sv t httpd-e-smith
So far everything looks OK; I'll report back here if I observe any problems with my SME.