There are plans for a coupon code module to hopefully be included in the next major release (version 3.1) which is tentatively scheduled for a September release date.. I don't have any information relating to plans for an affiliate feature however.
If these features are of great importance to you, have you considered a coder for hire who can customize your theme for you? The benefit of this is that you can get what you want right away, and avoid disappointment if the feature is somehow missed or time frames are not what was hoped for. We have a ClassiPress theme services thread
here.