First, I didn't read that thread the first time around - I posted this before that thread appeared.
But, while it's true that R&D costs are significant for this device, I don't think they're as relevant as the per-handset building costs - simply because they can spread the R&D costs over so many devices sold. They're estimating sales of 10m in the first year. (If sales double the following year, the revenue doubles, the build costs double, the R&D costs don't).
So if their 'gross profit' per phone is (if iSuppli is correct, at least) 249 dollars. Multiply that by 10m and they have 2.5 billion dollars from which to fund R&D, and still make a significant difference to Apple's year end bottom line.
If reports we've heard are correct, little of the hardware used was developed in house, which should cut down on development costs too.
