Good question, some thoughts to ponder on that:
The result of the Apple v Microsoft prevented Apple from holding a copywrite on the "look & feel" of a user interface. This would also apply to Microsoft.
For more info on the case, go here;
In the Microsoft v Lindows case, Microsoft basically lost their trademark on the "Windows" title.
To many links on this one to list, go here and scroll to the very bottom, then read from the bottom up. Makes for good entertainment (and laugh)
If I don’t like the picture quality Fuji film produces in my camera, I can get Kodak with out getting a new camera, flash, tripod, or darkroom. If I don’t like the Energizer battery life in my walkman, I can get Duracell with out replacing all of my tape/CD’s, getting new headphones, or a new walkman. Many electronics in the public sector can swap parts and features because of these standards.
Getting the functionality may require the same thing Phoenix did when they sold Compaq a BIOS that was 100% compatible with the IBM PC. The guys from Phoenix used two sets of programmers, one who had access to IBM's source code and another who could be proven in court to be source code virgins. The first group made a list of everything the BIOS did for a specific set of inputs, but carefully avoided any mention of the original code. The second group then took all those notes and wrote their own BIOS that performed exactly the same as IBM's, but completely from scratch without any possible contamination from IBM. If someone did this with the MS Windows OS, we may just get that 100% compatible OS.
The company that does this will need a lot of capitol for legal fees alone. Even though it may be a loosing case, Microsoft will still bring it to court and appeal it to no avail. If you can’t beat them, litigate the hell out of them so they go broke paying legal fees up the nose. Then again, Microsoft could surprise the world, do nothing in the legal system to stop a 100% compatible OS. They could just work a little harder on their OS, make it better, stronger, faster, rename it to Bionic Windows and win the market with a better product than the competition.
And pigs will fly