Hello!
Here is what I have done since 20090828 in 'hg diff' format:
http://swizard.info/misc/cl-prevalence-3.patch
It is going slightly uncomfortable for me to maintain patchfiles,
maybe I should make a mercurial branch or something?
Detailed changelog:
1. SEXP standard-object serializing: fixed a bug with no-slots objects.
2. Backup method for guarded-prevalence-system: key parameter bugfix.
3. Files external format support for prevalence-system with tests
available (test/test-external-format.lisp).
4. Moved from 'copy-file'+'delete-file' to 'rename-file' in snapshot
method. Have no idea why it was like that :)
5. Removed reset serialization context invocations in
serialize-sexp, deserialize-sexp, serialize-xml and deserialize-xml.
Context reset moved to 'snapshot' method.
6. test/test-complex-serialize.lisp: emulation of complex datasets
processing under heavy load.