There are updated packages in the Yum repository:

• PHP 5.3.6 (php) changelog
• PHP Pear 1.9.2 (php-pear) changelog
• Memcache extension for PHP 3.0.5 (php-pecl-memcache) changelog
• MySQL 5.5.10 (mysql55) changelog
• MySQL 5.1.56 (mysql51) changelog

What's interesting is that PHP.net decided not to release the security fixes to PHP 5.2. The security flaws that were fixed may affect that release, which is end of life, so I recommend that you upgrade to PHP 5.3. PHP 5.3 has now been out for almost 2 years.

Now that PHP Pear 1.9.2 is in the repository, you should be able to install PHPUnit 3.5 without needing to manually upgrade Pear.