Seriously this is too much. If they positioned themselves as not allowing you to have PSN services if you modded your console, then fine. Going against people who pirate games, fine. But targetting legitimate modding (including what can be 'dual use' which is another philosophical question in itself) when people have purchased the console themselves is a new low - it's now infringing on the rights of consumers to do what they want to with machines they purchase. If they are allowed to get away with this as others have mentioned it will set a whole new (lower) standard in how companies can restrict our inalienable rights. The whole concept of them promising the 'other os' option and then taking it away is poor.
I have to say Microsoft has behaved (from a console/gamer point of view) in a much more respectful manner in the past few years. I don't even think Sony has a natural advantage why you would want to buy their equipment, especially as others make better phones/tvs etc.
I'm calling for people to boycott Sony, not just games, but in TVs, cameras, and phones. Maybe they'll get a message that their anticonsumer tactics are not in anybody's interests.
As a public service aside I noted the linked article has broken download links for the 'hypervisor bible'. So I provide the following link for the Slashdot audience:
http://www.ps3iso.com/showthread.php?t=51100