I think that an awesome feature would be add a parameter, call it a product description or product review or even a comment, that could then be added to the template. For example, the shortcode would be someething like:
[asa prod_desc="This is a cool book!"]ASIN0000[/asa]
And when the product was displayed, „This is a cool book!“ would appear inside the product box.
Thanks for your consideration.