Hey Jun, cool script! Just upgraded three 4.6.3 instances and one from head from PSQL7.2.4 to 7.3.4, with hardly any trouble. I came across another couple of functions that are missed by the script though, from the surveys package. For reference, these are:
survey_response__initial_respon
needs to be replaced survey_response__initial_response_id
survey_response__initial_user_i
needs to be replaced by survey_response__initial_user_id
Sorry I can't offer a patch to the script!