Even though the checkout form link is not directly available to the end-user if he/she should happen to go there it would be nice if the form were so smart as to first check if the user actually has any products in the shopping cart.

Currently this is not the case and users (hackers even) can 'order' an empty shopping cart. So they order nothing really. Still inconvenient should this happen.

I guess this would require a custom model class and/or custom template script to check against this.