Don't panic. I am sure the situation is less worrisome than you are making it. So much that, according to the letter and other e-mails, the guy disappeared about a year ago, and for this whole time the project went on, many new versions were released, updates kept showing up as usual. As I see, the main issue here is on the domain name, if the guy does not show up and cooperate, the project might have to see the registrar on how to transfer it to another person, or in a last case change the domain to centos.net or centos.com or something like that... The would not be desirable as it would break yum config, etc., but it's far from the end of the world. I really can't see how this issue could bring an end to the project. HTH, Filipe