The idea with CentOS (and RHEL) is that they are really enterprise oriented. That means, practically speaking, that they are designed to run what are generally considered server apps, e.g., Apache, LDAP, an SQL, whether MySQL or yourSQL
(sorry, couldn't resist).
So, the most important thing for them is to be a stable platform that doesn't change, and, if a program will requre changes to the configuration files, don't include it.
Therefore, often you will find them behind in versions of various and sundry, such as gcc where they have 4.1, for example--so you can't build google's chromium browser which requires gcc 4.2.
This is the somewhat long winded explanation for why you will have packages that seem out of date.
You might try asking on CentOS forums about it, though not sure if you'll get answers or not.
(Not that they're rude, just that the majority of members are probably sysadmins, so don't install newer versions of something as intrinsic as python--as yum makes use of it, it's pretty important.)