In Solaris 10 it was easy, a simple grep through modinfo output and you'd have the version of any loaded module, including your NIC drivers. In my career I've seen many people relying on this information in their scripts. Now I'm on Solaris 11, and where have the version numbers gone? The modinfo output on Solaris 11 no longer yields version numbers.
To save others from the trouble of having to figure this one out, I've written up my notes on how to solve this particular puzzle that I hope will be of use to someone else.