I have been looking at belief revision when belief states are represented as default theories. Both my PhD dissertation and my ECAI-98 paper discuss how this approach enables us to implement persistent contraction, context-sensitive choice functions and mechanisms for retaining beliefs which would otherwise be discarded in anticipation of future re-use. It makes it easy for belief change operations to be reversible/recoverable (I'm not convinced that this is undersirable, as some maintain). Non-prioritized belief change operations are easily defined in this approach and the problem of iterated belief change finds a simple solution (with provably minimal change over iterated steps being an additional bonus).