Aside from the Gpk Application, Yum Extender, another graphical package manager, is in the repositories. Unlike the Gpk Application, it requires authentication to start. Multiple applications may be queued for installation on both graphical installation programs. Yum Extender presents a better interface, but it is slower than the Gpk Application.
Yum Extender CentOS 6

Graphical Administrative Applications: Most of the graphical administrative applications that could be used to manage the system are accessible from two menu categories – System > Preferences and System > Administration. A few are accessible from Applications > System Tools.

The Users and Groups management application is the major one under System > Administration. It is a fully-features user management tool, supporting account expiration and password aging, two security features you expect to find on a good user management tool.
CentOS 6 User Manager

Network Security Applications: A new installation of CentOS 6 has four open ports – 22 (SSH), 25 (SMTP), 111 (rpcbind), 631 (IPP). I do not expect port 25 to be open on a desktop distribution, but remember that by default, CentOS is a server distribution, so these ports, especially port 25, are what you should see on a minimal (server) installation.

The graphical firewall client, the same available on Fedora, is enabled and configured.
Graphical Firewall on CentOS 6

Final Thoughts: This was just an excursion to determine whether CentOS 6 could be a good candidate as a desktop distribution for non-experts, or new users. The verdict: Unless you do not mind getting digital grease on your hands, there are better RPM-based distributions available. Fedora or any Fedora Spin, makes a better desktop distribution than CentOS 6.

Resources: 32- and 64-bit installation images for CentOS 6 are available from the public mirror list. Support questions may be posted here and at Questions and Answers.

Screenshots: More screenshots from test installations of CentOS 6 Desktop.

As noted earlier, Firefox 3.6.9 is the installed version of the popular Web browser on CentOS 6. This screenshot shows the entry for Firefox and other Internet applications installed by default.
Internet Applications on CentOS 6

LibreOffice has not reached CentOS 6 yet, so the default office suite is still OpenOffice.org.
Office Applications on CentOS 6

Default system tools on CentOS 6
 System Tools on CentOS 6

Sound and video application installed on CentOS 6
Multimedia Applications on CentOS 6