revealed about a month prior to the iPhone... shipped a few weeks before the iPhone...If only the cause-and-effect were so clear. The iPhone was rumored for years before it was released; it was surely in manufacturing prototype for many months before it was announced, and then it was announced months before it actually shipped.
Apple is legendary for keeping its secrets well. But even major government agencies can't keep secrets perfectly. Espionage works. And I'm sure that lots of people in China were in a position to figure out Apple's plans in advance. (Note how poorly the iPad's secrets were kept relative to the iPhone. The biggest advantage Apple had with the iPod and iPhone was the element of surprise: Nobody thought of Apple as a music-player company, or a telephony company, so nobody was focusing too hard on Apple product espionage. They're focused now, though.)
So the argument that these various contemporaneous iPhone-like devices would have happened without the iPhone is pretty weak. For example, just because Google and Microsoft announced iPad knockoffs within days of the iPad announcement [1] doesn't mean that those products [2] were going to happen with or without Apple.
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[1] Microsoft's pad was announced earlier! Of course, I'm told it also didn't look much like an iPad. In demo-theatre, as in curling, it pays to move last.
[2] If products they are. Demos are at least one order of magnitude easier to cough out than shipping products are. Of course you can build a demo of a pad. That's a couple weeks of work or less.