- Add keywords for transaction access mode and isolation level to with-transaction
- Add support for cursors?
- Add large object support
- Add namespace support for types?
- Add serializers/deserializers for the "hstore" data type?  (Probably map them to hashtables)  This is a Postgres extension, not part of core so not sure if we should support it at all.

Important features from the upcoming PostgreSQL 9 release:
- Add support for PQescapeIdentifier
- Replace PQescapeStringConn with PQescapeLiteral, this uses less memory (or at least makes it Not Our Problem). Unfortunately it puts single quotes around the string, which PQescapeStringConn didn't do....
- Use PQconnectStartParams instead of PQconnectStart call when an alist is supplied instead of a connspec string

These are very neat, but when can we start requiring them?  In other
words, when will this library be for PostgreSQL 9+?