Midrange Computing has an article, What's New with DB2 in V5R2.

I've mentioned some of the SQL enhancements before, but the MC article covers more, and give examples. I don't know about you, but I find examples so much easier to comprehend. There are also SQL enhancements mentioned that didn't make it to the IBM document - The CREATE TABLE LIKE command, and the more flexible ORDER BY clause. Genuinely useful stuff.

Also new at V5R2 is the JDBC 3.0 support.