@Patrick,
CentOS is actually a clone of RHEL (RedHat Enterprise Linux) with all the RedHat branding taken out. Many companies with competent Linux admins use CentOS instead of RedHat, saving them the maintenance contract fees.
@mel & kona,
Yes, it's e17. I purposely chose that desktop over all the others. Mageia keeps it updated even more quickly than Bodhi does. As I've said before, I've been using e17 for years. It's a very fast desktop, easily equivalent to Openbox, with lots of eye candy.