"[...] the fact that the developer community has embraced the iPhone platform so willingly spells bad news for Microsoft in the Mobile OS department because it means developers are happy to abandon Microsoft if the monetary rewards lie elsewhere."
Your premise is flawed in at least two ways.
First, I suspect many of the iPhone developers were never Windows Mobile developers in the first place, but people who saw the promise of the iPhone and wanted to get in on the ground floor. So saying they "abandoned" Microsoft is like saying you abandoned the Presidency.
Second, while there are several Windows Mobile developers who have produced or are working on iPhone software, that doesn't mean they've stopped working on Windows Mobile software. It just means that they're branching out, seeking new revenue streams and/or hedging their bets. In fact, if a company is actually hiring new developers to work on the iPhone, that's the best of both worlds -- both platforms get software and more programmers get jobs.
But, just for grins, what well-known Windows Mobile software companies or developers (meaning they've had at least one major, successful WinMo app) have actually stopped developing Windows Mobile software to work on some other platform (not just the iPhone)? If the answer is "not many", you should retract your claim.
Steve
Will the Mobile World Push Microsoft to Irrelevancy?