Lots of good reasons to move to 8.3 sooner rather than later.

From 2008.08.29 bobg says

I ran into yet another reason to get to postgresql 8.3, they finally (actually 
in 8.2) extended inserts so that you can return the primary key on insert.  
Before 8.2 (and what we use) "usually" works.  In 8.3 we can 
INSERT INTO ... RETURNING id.  The returning clause is a postgres extension to 
sql.   Mysql added this extension quite some time ago.  Not sure why it took 
postgres so long.

I would really like to move to 8.3 as soon as we can, but not now if it means 
bumping our schedule.

Bob