after reading a lot lately about Import/Export issues/requests I thought a API would be a very usefull feature.
Use Case 1:
You have a third party programm taking care of the fullfilment (stock management, shipping, etc). You can use the Magento API to change order status. Customer logging into their account can see current status based on what the third party software transmitted.
Use Case 2:
Your third party stock management can update your Magento Store stock management on demand if a product is sold outside of the Magento Store (e.g. in a real walk in shop).
Aim:
This way, both databases are allways up-to-date, a minimum of traffic is generated and every transaction can be made in real time. No discrepancies in walk-in and online stores.
There could be some other nice cases for this which I don’t want to go in details now. Would be great to know if Magento guys are allready planning on integration such an API or if this would be left up to the community.