Hi Chris,
Vendor stores is the new feature in pro that will allow us to create a Vendor front page instead of only hooking into the product archive. This will allow us to have more control (in future updates) as to what is displayed on the vendors store page. In a future release, you will be able to allow vendors to have ‘featured products’ on their store and other widgets. There will also be store based categories so that you can browse the store’s categories only.
Vendors is what free uses to hook into the basic store layout.
cheers,
Jamie.