Example from page 75 of Frederick Schauer’s *Thinking Like a Lawyer*:

>But **what of** mandatory authorities? Are they as “binding” as the traditional
terminology suggests? The answer depends on what is meant by
“binding,” and it turns out that speaking of “binding” authority can be
just as misleading as speaking of “persuasive” authority.

What are the similarities and differences between *what about* and *what of*? I see that the [definitions](http://www.learnersdictionary.com/definition/what) below are worded differently, but I don’t see any intrinsic differences — which I still suspect must exist. 

>**what about**
1a. does that include (someone) : how about (someone)  
1b. how does that affect (someone or something) :     
2. used to make a suggestion about what could be done  
3. used to ask someone to tell you something in response to the thing that you have just said  

>**what of** 
1. *formal* how does that affect (someone or something)   
2. why does (something) matter