The Cloud and the SMB: Diversified?

I was reading the post Small Business Virtualization and that really got me thinking about Small to Medium Businesses and what part Cloud Computing will play in that market. There are plenty of small businesses in and around my area and I have a couple of friends that are the owners of a couple of these small businesses. A majority of these small businesses have a single or a couple of point of sale machines that feed to the accounting program. It is these businesses that I think of when I think of what a small business is. Would virtualization help these companies? Sure, I think so but would it really be worth the cost to setup and maintain?