I believe there have been a few, but I'm not aware of any being quite as public. Since the others weren't public, it's harder to know exactly how far the attackers got.
I do know for certain that at least one other service popular among domainers has been compromised recently, and the credentials obtained during the attack have been leveraged to gain access to NamePros accounts, since people tend to use the same password for all their accounts.
The argument for assigning some degree of blame to Epik is that some of their security practices appear to have been bordering on negligent. However, that assessment is based exclusively on data that an attacker published. Conveniently, the majority of the passwords/hashes appear to have been removed by the attacker. For all we know, they could've been proper hashes.