If they do Starter Edition again, I agree that it is unlikely to be targeted to or even released in the US. Even excluding AV/Firewall apps from this completely fucktarded 3 app limit, I'd imagine that the group of people in the US getting computers from OEMs like Dell, particularly laptops, could include a sizeable amount of high school and college age people.
These people are very likely to use media player, a web browser, and MS Word simultaneously all the time. a 3 app limit is completely bonkers. They may also want to run background apps like AIM, Skype, Bittorrent, email client (If they don't just use gmail web interface), etc etc.
Restricting the main stream Windows would be epic fail for MS in that kind of market. If it really is targeted as the generic OEM version like Vista Home/XP Home is now, it should support at least 5 or 6 concurrent apps so students don't have to close AIM to write a paper, or ever have to choose between totally normal behaviour or restricted crap like that. It'll just drive up piracy of WinXP even more, or drive up support calls and angry customers.