I believe there should only be the one client product:
Windows 7 Client
The Business/Ultimate/Basic/Premium thing is just a giant PITA, particularly when you have people being sold Home system with a "no worries" salesman assurance they can hook up to the domain at work, and downgrade to XP of needs be.
Sell the "premium/ultimate" features as an add-on pack, and then standardise on a single client platform, so that the price remains the same for business users, and so that the home/business confusion is removed.
So long as you can set a simple personality switch, to set the preferred mode - Home User, Business User - then people can make it work how they like/need, without the issues * buying a notebook and finding that your IT dept won't help you connect it to the domain.