So you're talking about cloning, not copying. Like Windows is a VMS clone, BSD is a UNIX clone, Vista's UI is an OS X clone, etc.?
Thankfully, patents will probably stand in the way
Windows likely violates several patents held by the Open Invention Network, including key Web services patents that could seriously hurt Microsoft. Oracle is also a member, so Microsoft had better watch out for what patents SQL Server violates. IBM is also a member, and they have more software patents than anybody else.
Software patents are a double-edged sword, so Microsoft is playing with fire. There is NO application of any decent complexity that does not violate somebody's patent, and Microsoft has a lot of complex applications out there.
Not nearly in the same context as Linux is a copy of Unix. Nor are there employees working at Apple giving their code to Microsoft to use in Vista, Microsoft actually had to write the iPod software itself from what I've heard. Nor would that be a transfer to a foreign government. China based their "Red Flag" software on a direct copy of "Red Hat" which is based in North Carolina. Not as if you didn't know, but especially to claim Vista is a copy of OSX as a defense in this context is far from the mark.
Microsoft had better watch out for what patents SQL Server violates. IBM is also a member, and they have more software patents than anybody else.
Yes IBM has history of aggresively using software patents, just as with their recent suits including one against Amazon which was settled in IBM's favor. Microsoft doesn't have a history of aggressively suing others, but I would think this would be an appropriate moment from their perspective, would you not? With IBM launching its own patent suits seems like the opportune time actually.