I did a mock-up quite some time ago that is very similar to Tammy's Holder theme. I am including a link to it here. Some things that would be nice additions under Holder Options would be fields for email, phone, and address which could then be mapped. Additionally a place for business hours.
With what Tammy has already done so far with Holder that would make it pretty darn complete for most any traditional brick and mortar business.
Adding front end editing would take it to a whole different level. Imagine being able to offer users with low technical skills a site that they could set up themselves without having to ever see the dashboard.
Users could then be offered and select upgrade options, from the front end, similar to the Prosite concept. So a blog or extra pages might cost extra.
This could be a whole new project based on Holder.
In my case I would prefer the option to be able to select a standard site theme style from the back end. Or select the choices offered on the front end. The logic for what I have in mind is to use a standard format that visitors will recognize and can easily navigate. Yet at the same time have it customizable enough that each site can have it's own personality. A good analogy is the automobile. When you get in you know where the accelerator brake and clutch are even if the style of vehicle is very different.
I would be happy to volunteer on the project if Tammy and WPMU DEV are interested.