Don, honestly I don't know all the details. I just know it's broken because Bart told me so and because of a quick examining of the oracle datamodel.
For example, the service contract definition files are absent from the ecommerce/sql/oracle/ directory. I am comitting to fixing the Oracle version as soon as I finish this project though. I have some Oracle installations at work that I can use.
Regarding the date semantics in PG, I couldn't agree with you more. I wish they had made the milisecond precision thing an option, because I think most projects really don't need it.