Some more items from my list which have been added since v6.2.1:
SQL92 binary and hex input and string type coersion
allow casting of non-constants using both SQL92 and Postgres syntax
parser support for PRIMARY, FOREIGN KEY
backend support for PRIMARY KEY, UNIQUE (create index)
more parser support for DEFAULT, CHECK clauses
add 'doy' as argument to datetime_part()
functions datetime_time(), time(datetime)
functions int4_datetime(), int4_timespan()
add unixdate package to contrib area
constant CURRENT_USER as GetPgUserName()
support SQL3 syntax TRUE, FALSE
implement IS TRUE, IS FALSE, IS NOT TRUE, IS NOT FALSE
provide timezone support in libpq and backend
support SQL92 "delimited identifiers" (libpq, scan.l, psql)
PGTZ environment variable for frontend
fix session initialization from front-end environment variables
use PGDATESTYLE to initialize backend at startup
add GERMAN date style
allow alternate locations for databases
add hash functions for datetime, timespan
fix hash function declarations for float8 and int4
convert text to/from int4, int2
Also, we've added UNIONs (didn't see it on Bruce's list).
- Tom