Actually catalog of common Common Lisp idioms. Some idioms are generalizable for all major Lisp dialects. Another nice idea for ELS 2010.
reduce map with-x defx or def-x dox or do-x <conditional-operator>-let or b<conditional-operator> [b is for binding] ...
Provide examples from SISCOG code base?
Each pattern should have an associated implementation strategy for being defined with macros.