Regarding the "idea to think about":

David, you are I think proposing some modern analogue to books such 
as Readings in Monetary Theory (1951) and Readings in Business Cycle 
Theory (1951).  These books were clearly produced to support exactly 
the kind of graduate field exam prep that you mention.

For comparison, it might be worth thinking about the Elgar volumes 
such as Foundations of Monetary Economics (ed. Laidler 1999) or 
Foundations of Business Cycle Theory (ed. OBrien 1997).  I assume 
these were modeled on the Irwin Series, although (crucially?) I don't 
think they had official AEA imprimatur.  Another difference, the 
Elgar volumes were intended (and priced) as reference volumes for 
library and specialist purchase.

What you have in mind, I think, is something aimed more directly at 
the graduate student.  From this point of view it might also be worth 
thinking about the CEPA web site which seems not only aimed at such 
students but also largely produced by them.  This is the demand side 
of the market you want to serve, but also a non-book medium that 
might be worth considering.

Perry Mehrling