Some businesses have their own Certficate Authority and sign their code with that. I can't speak for businesses that run OS X primarily, but there are Windows shops that do so. Microsoft includes Certificate Services with Windows Server for those that wish to sign their own certificates, rather than relying on third parties. If Apple will sign in-house applications without any validation process of code, then it won't make any difference for those customers. From what I understand about iOS apps though is that the software goes under some evaluation process, to ensure it is safe and whatnot, before it certified. You can't really expect to do business with private corporations that write their own in-house software if it is to go under evaluation by a third party. A third party really has no business in telling companies how their in-house software should function or be secured. I can understand the need for commercial apps, but not private apps. Regardless, we don't know at this point if the software must be signed by Apple or only by any trusted certificate authority. Windows has the same builtin security (only enabled for hardware drivers by default), but it only requires code to be signed by any trusted authority, not just by Microsoft. I believe non-driver apps unsigned or signed by an untrusted authority will prompt the user to verify that it is "safe".