Carnage Blender is still running 3.2.5-derived code, on PG 7.4 as of last month. There were a bunch of incompatibilities but it wasn't as bad as moving from 7.0 to 7.2.
On the other hand my three favorite features are
- the planner for IN is now smart and you don't have to rewrite all your subselects as EXSISTS queries
- queries on views with UNIONs in them use indexes
- '2 minutes' no longer requires an explicit cast to be an interval (hey, the little things count :)
