So we want to issue machine certs to company assets to distinguish between company and non-company systems. It appears that machine cert checks are not available for the above mentioned platforms. It appears machine cert checks are only available for Windows and Windows Mobile.
Is this a true statement? If so, how are others establishing if an asset is company issued or not (This is easy on Windows since host checker can check for lots of things but the other patforms seem lacking)?
Yes, that is a correct statement as the other platforms do not have the concept of a machine certificate; a certificate is a certificate is a certificate.
The most common I have seen is a certificate issued by the company. On OS X, you can do a file check for a file you place on the system. You can make this hidden (using a . in the name, placing the file in the non-GUI locations on the file hierarchy, or both).
On the iphone, I believe that the profile can be set as non-exportable so it must be installed prior to delivery. I do not have access or exposure to the other systems to comment.