Also keep in mind RHEL3 has about 3 years left of its life before its EOL'd, perhaps thats what the other project means. As soon as RHEL stop providing support, CentOS would EOL as well.
Three years ? No, as RHEL3 was released October 2003, RHEL will be supported for more than 5 years from now. RHEL is supported 7 years after it's release (used to be 5 years though)
With regards,
Taco