What is the difference between SUA and SAA?
SAA is a project being undertaken to unify how SUA's (and ATCAA's) are defined, managed, and shared.


  
  [SAA will] define SUAs and ATCAAs in a consistent manner using an editing tool
  Use a Service Oriented Architecture (SOA) to distribute that data to interested users
  Manage the schedule and status of those airspaces through a SOA.
  


SAA is part of the System Wide Information Management (SWIM).

In short, SAA encompasses SUA, ATCAA, etc.



Source: SAA Modernization (.ppt file)