A simple addon that will allow comments to be added to product listing, to the MarketPress Ecommerce Plugin.
You can get MarketPress plugin from WPMUDev.org website.
Short answer: maybe.
By all means please contact me to discuss features or options you'd like to see added to the plugin. I can't guarantee to add all of them, but I will consider all sensible requests. I can be contacted here: http://alex.frenkel-online.com/