I'll take you through it step by step, ok? And since this really IS informative and should be modded +5, I fully expect to be evicerated into trolldom by the idiots that modded you up.
Section 1 states: Every contract, combination in the form of trust or otherwise, or conspiracy, in restraint of trade or commerce among the several States, or with foreign nations, is declared to be illegal.
Apple never claimed to support WMA and does NOT have a monopoly on music sales or formats. Microsoft DID claim to support other vendor's software, and in fact did support Netscape until they decided to push Internet Explorer, at which time they disabled Netscape from functioning to restrain it from competing in the same space. This is where the Standard Oil comparison comes in, but with Microsoft playing that role - they own both the OS and a browser, and strongarmed a competing browser from running on the OS. Apple does not own the major format (mp3) or the only way of getting music onto an iPod (I can think of three different ways to get this done without iTunes - see links at bottom).
Section 2 states: Every person who shall monopolize, or attempt to monopolize, or combine or conspire with any other person or persons, to monopolize any part of the trade or commerce among the several States, or with foreign nations, shall be deemed guilty of a felony, and, on conviction thereof, shall be punished by fine not exceeding $10,000,000 if a corporation, or, if any other person, $350,000, or by imprisonment not exceeding three years, or by both said punishments, in the discretion of the court.
Again, same thing as my paragraph below section 1. Microsoft attempted to monopolize through their control of the OS. Apple can't monopolize something they don't have a monopoly on. These are two wholly different situations.
Section 3 states: Every contract, combination in form of trust or otherwise, or conspiracy, in restraint of trade or commerce in any Territory of the United States or of the District of Columbia, or in restraint of trade or commerce between any such Territory and another, or between any such Territory or Territories and any State or States or the District of Columbia, or with foreign nations, or between the District of Columbia and any State or States or foreign nations, is declared illegal.
Oops, there it is again! Microsoft- restraint of trade: competitors actively stopped from competing. Apple, unable to restrain trade because it can't restrain something it doesn't have complete control of: there are at least six different alternatives to iTunes that I know of, three of which I've often seen installed out of the box on Windows PC's. I can't count the number of alternative music players that are as easily available and in most cases far more affordable than an iPod.
The rest of the sections define the rules for proceedings and limitations on this law.
When it comes to dominant userland OS's, Microsoft not only has the most distributed OS on the planet, but has actively stopped (to a large extent) competing OS's from even being a choice when you order a pre-built PC (another monopoly that they've gotten away with, at least in the US). Apple has the most distributed music player on the planet, but not because they forcibly removed others from being choices, rather they made a decent product and successfully marketed it. Nobody is forcing you to use iTunes to buy music online. You could just as well purchase it through, say, Windows Media Player. If you saved it as mp3 (hey, don't want to get all monopolistic now!) you can move these songs into iTunes and put it on your iPod. Try getting an iTunes Store or WMA file moved onto your generic mp3 player. Won't happen without some third party apps, and then I only know how to make it happen with the iTunes files (because I haven't tried with WMA).
Oh, and last but not least: the plaintiff's aren't asking for Apple to pony up licensing fees. That's the beauty of the scam: if Apple does it, Microsoft gets their money and these lawyers get to look like they 'struck a blow for music lovers'; if Apple doesn't do it, they look like corporate snobs who don't care about their user base. This is such an obvious bullshit scam I can't believe anyone let it get as far as the trashcan next to their desk. I've seen more subtle emails from my rich Nigerian uncle.
Here's some interesting stuff to read:
http://en.wikipedia.org/wiki/Comparison_of_iPod_Managershttp://en.wikipedia.org/wiki/Comparison_of_online_music_storesAnd the section related to Standard Oil's monopoly charges:
http://en.wikipedia.org/wiki/Standard_Oil