The open letters will have been written by a PR person and the vouchers have nothing to do with being Steve being a good person.
It's just a very clever business move to try and stop people getting too pissed off with Apple.
They've dropped the 8GB iPhone to $400. IIRC, it only costs $300 to manufacture doesn't it? So all that means is they're gouging less.
Apple will still be getting their $200/phone off of AT&T, their slice of the contract and now sales will probably see an up-turn.
They should hang on to those gift vouchers, they'll need 'em in 6 months when they have to pay, what is it, $80 to get the battery replaced?
And then a further $30 or so to rent a spare iPhone whilst it's away...
Apple doesn't care about their customers, just about money.
If you need any more proof, how about the adverts they had on Google earlier:
[Courtesy of SearchEngineLand]
Who's the company commiserating with the early adopters? Nokia.
Who's the one basically pointing and laughing? Apple.