(Note that many of these links are rather old and may not be accurate) Is MySQL really this bad - Ars Technica Comparison Matrix (includes Apache Derby and One$DB) Comparison of MySQL 5.5 and Postgre
(Note that many of these links are rather old and may not be accurate)
Is MySQL really this bad - Ars Technica
Comparison Matrix (includes Apache Derby and One$DB)
Comparison of MySQL 5.5 and PostgreSQL 9.0 replication
[edit] Pro PostgreSQL
Related article on Command Prompt: PostgreSQL vs MySQL @ Oracle NYC Head Quarters NYC (my brain just broke)
PostgreSQL Connection strings
Why PostgreSQL Instead of MySQL in 2009
Transactional DDL in PostgreSQL: A Competitive Analysis
[edit] Pro MySQL
Hi-Def Video of the HuffingtonPost CTO discussing Enterprise MySQL: Heavy-Traffic Management and Ultra-Availability at the NYC MySQL Group at Sun Microsystems