Java (J2SE 5.0) and C# Comparison
C# vs Ruby Smackdown!
SQL Server 2000 vs Oracle 9i
A Comparison of PL/SQL and Transact SQL
and last but not least:
Comparison of SOA Suites
Note there is an ESB implementation from P&P for BizTalk 2006 R2 that sort of leverage the missing functionality in the product: ESB Guidance for BizTalk Server 2006 R2
Ok, there’s nothing new here, just a personal cheat sheet :-p