So the premise of the question is to quantify the risk of wild card certificates versus regular certificates. From my research the greatest fundamental danger of wild card certificates is the possibility of compromising a weak system, getting the private keys then you can masquerade as any system. For this to work you have to compromise a system and compromise the public DNS server(assuming this is an Internet based attack) and do so before the certificate is revoked.
It occurred to me that if the requirements of certificate authorities for verifying companies validity changes, where some are easier to social engineer then others, it may discount the risk of Wild card certificates. That is, it may be easier for someone to social engineer a CA then it is to break into a system and steal the private keys. Further the named Certs may foster a false sense of security as they may be mimicked by another trusted authority. This also creates another issue where certificate revocation is out of the hands of the company, where a wildcard could utilize it.
What I have not been able to find is a standard that root Authorities must follow when verifying client domains. Is there a standard they must follow? If not does anyone know a list or site of the different verification requirements of each CA?