Unless Linux developers begin purposely infringing on major Microsoft patents, Redmond will not go after Linux regarding the famous 235 patents they claim the penguin already violates. They’ve waited too long; that can no longer happen. To go after Tux now would be something akin to suicide and might possibly relegate the software giant to being simply another consumer software company. Ballmer knows this; Red Hat probably knows it; the rest of us suspect it.
The reason for this centers around the enterprise. No matter how pervasive Windows may be in the consumer market, they can’t live on the money they make from supplying binary for home computers, especially given the fact that most consumers receive all their Microsoft products preinstalled when they purchase their boxes. The Microsoft tax on consumer products is hardly enough to keep the world’s largest software maker afloat, and it’s a tax they can’t raise much without creating a revolt by both consumers and OEMs that would move personal computing to Apple and Linux.