I'm going to call B.S. on the letter. Not to say it wasn't interesting (though the oil platform story was just horrible writing) but it just isn't plausible. It is probably not a "hoax," but someone's in the USA's attempt at writing a what-would-Elop-write letter that got passed around and the provenance was lost.

Nokia's biggest competition is Samsung. Whether using Android or Meego or Bada or WP7 or Symbian, the biggest smartphone problem Nokia has is not outselling Apple, but continuing to outsell Samsung. They have at least a year, possibly even two, before Samsung can possibly catch up with them in market share, and they are currently profitable. They have plenty of breathing room and are not on a sinking ship or burning platform.

I don't see any reason why Nokia would adopt WP7--either from this supposed Elop letter or in the real world. I can see the seductive lure of Android, but I suspect that long before they created an android phone they would develop a free Qt or QML implementation on Android and WP7 and then would spend tons of money getting some big-name developers to start using it. That would leverage their existing investments, would not require them to retool their entire production and support infrastructure to handle a new OS, and would build on their currently profitable business lines.

If they do decide to start working in the US again, expect to see E7 and the C-series phones start displacing blackberries and cheaper phones-with-facebook.