If you absolutely, positively must have these updates, you might look into using Jason Litka's excellent repository, which includes patched PHP 5.2.5, httpd 2.8 and MySQL 5.0.58
Not supported or recommended by the folks here, of course, but very useful if you must have a very up-to-date CentOS.
http://www.jasonlitka.com/yum-repository/changelog/You'll need to do a bit of research to figure out how to enable and use his repos, and your following yum update will be scary as it'll replace a load of packages and modules. Caveat Emptor... but I've had very good luck with it and he does seem serious about changes and updates.
Time Will Tell... hopefully he continues his good work, it is much appreciated by those who use his repos and builds.