Cluster Management: Maintaining a large number of Apache servers has never been helped by the servers native capabilities but we do have some choices.

Think of httpd.conf as content

One could take the IP/host specific directives out of the httpd.conf, use a universal httpd.conf but use the Include directive to get the IP/host specific directives from an external configuration file:
Include /path/to/my.conf
httpd.conf could then be a centrally managed file that could be regarded as content and therefore maintained with rsync or rdist.

NFS mount the httpd.conf

Have a central source export a mount for configuration items. This brings with it all of things one might find distasteful with NFS but it effectively centralizes the configuration.

Use mod_perl

Even if one is not using all of the other things that mod_perl is good for, one could use it to configure
<perl>
</perl>
stanza's that include connecting to remote databases and/or doing all of the other cools things that Perl does with little effort.