I disagree. Licensing is quiet different from building, developing and implementing systems or databases. Ofcourse, dba's will be asked about licensing, but I think this is rarely the case. It will happen as much as a VB developer will be asked about VS.NET licensing. Most orginizations I have worked have a dedicated manager taking care of licensing. And, with dedicated I do not mean this person is only busy with licensing.

We're talking about MS licensing. It could be there is a Certification track for just this subject...

Since licensing covers far more than just SQL Server it's not realistic to ask such questions and expect DBA's should be able to answer SQL Server questions. I have been at companies, where they had a package agreement with MS including a lot more then SQL Server licensing. In such companies the standard answers concerning licensing do not aply. Have you search BOL on licensing? And did you know then what license to take?

So let's skip these kind of orginizational/manageral questions, and stick to SQL Server questions