Hypothetically, I buy a MSFT abbreviated OS to do security work. MSFT sells a camera program I can use for my security. Watch and monitor my warehouse betweeen certain hours, detect motion, sound alarm, stuff like that. MSFT discontinues the application for whatever reason (which is not uncommon). My intent to use this PC remains the same, now because the competition uses functionality that is intentioanlly 'locked out' by the OS I purchased; I am blackmailed into purchasing another OS to upgrade my security system, which will ultimately perform the same function. For example, I add facial recognition to see that my workers are the only ones moving stuff out the front door.
The stance would be that the hardware was capable of running competitive software, but MSFT used their 'monopoly' status to force me to continue to purchase their products, in an anti-competitive nature, for me to perform a set of functionality that 'could have' been unlimited.
Substitute 'Security' for 'Animation', 'Photoshop', Circuit Design, Media Center, Gaming or whatever. In addition to magnifying the service support efforts (as if XP Media Center, XP Pro 32bit, XP Pro 64bit, Vista Home 32 bit, Vista Home 64 bit, Vista Ultimate 32 Bit, Vista Ultimate 64 bit, Vista Pro, as well as every variety of Win7 - 13 versions there alone) they will not have to support sub-sets of their OS's. This is a can of worms no one should have to open.
OK, didn't think of that scenario. Please don't misunderstand, I think this is a terrible idea, I just didn't see any avenues by which this would lead to litigation. Another lawsuit possibility is when the stuff malfunctions and doesn't let you run the stuff you ARE supposed to be able to. MicroShaft is notoriosly bad at authorization-enforcement-software, witness the WGA fiasco.