I'm developing a new payment module for a new payment method that is similar to a debit card and ideally it will work alongside any future credit or debit-card module(s). Is it possible for a single order to utilize multiple payment methods? This doesn't seem possible with the database configuration in version 1.3.7.1. Will this be possible in future versions?

Where should should the new payment data be stored for the order? For the time-being the order.cc_* fields seem most appropriate though it may conflict with future versions if credit/debit cards are also accepted for the same order.

Adding new fields to the order is another solution, however, it is not obvious how the merchant would get access to the new fields.