I'm no advocate of government intervention in a competitive environment, even in the case of a (perceived) monopoly. Competition is probably always the right answer, and it's certainly interesting to see this competition increasingly coming from unexpected sources. Lawrence Lessig compares the various Microsoft issues with the current ‘network neutrality‘ debate.
“I think about this mistake whenever I think about the current Microsoft-like network-neutrality debate – whether network owners can pick the stuff that flows across “their” network. In this debate, too, I am a reluctant regulator. And again, I don’t see how it’s possible to steer broadband providers away from a business model that – like Microsoft’s – may benefit them but could stifle innovation. Every dominant commercial competitor has the same incentive: to build a business that extracts all potential value from the pipes that company owns.”