When I discussed why there is no all-encompassing superset version of Windows, people somehow interpreted this as an explanation of why there are so many versions of Windows Vista. I guess these people never even made it past the title of the article, which argues for fewer Windows versions, not more! Besides, the article talked about the server side of Windows, not the workstation side. The target audiences for servers are very different from the target audiences for workstations. (At least some people were able to follow my point.)
The list of Windows Vista versions was news to me as much as it was news to you. It's not like everybody tells me what's going on at this company, or that I'd have the time to keep up on it if they did! (There's so much going on here, I can't even keep track of what my colleagues on the shell team are doing, and they work on my hallway! When I want Windows news, I turn to Paul Thurrott just like everybody else.) At least it appears that the people who want the all-encompassing superset version of Windows Vista Workstation will have their wish with the "Ultimate" plan.