I'm surprised there's not more positivity around this. I don't feel qualified in either Umbraco or NopCommerce to offer suggestions as to the implementation but can you imagine how fantastic a solution this would be bearing in mind the strengths of both platforms?
Please forge ahead with this guys ASAP. I for one am eagerly awaiting this to come to fruition and will be sure to use when available.
100% Agree...this is a great idea!