Dynamic Price and Product Visibility
Say there are 3 types of customer - general public, client a and client b. The general public don't need to log in to view products but client a and client b do. Additionally, client a has one set of products visible and client b has a different set of products visible with some of the products available to both groups but at different prices. A plugin that would serve this would be amazing - sort of cross between wholesale pricing and catalog visibility.