How can this be do to a strong dollar?
The strenght of the dollar can only be relevant if the product is actually made in the US.
As far as I am aware more or less everything is made in China. So unless the Chinese currency is following the dollar the production prices has actually gone down for apple, do to the dollar going up compared to the Chinese currency.
The argument makes no sense.
And on top of that... Apple doesn't take the money 'home', that is, where the HQ is: USA. They keep more abroad than in the US, to avoid paying taxes.
So in the end, Apple is even cashing more in case of currency fluctuations as they just can buy/sell the currency they prefer any time.
Or in other words, the currency is the excuse... should the currency weaken, they won't update the prices so quickly.
But in any case, it doesn't matter much for Apple I think. Thye are aware that a weak EUR (or a strong USD) is just good for one side, the weak one, and it is already a fact, EU companies are selling like crazy while US based ones are having trouble to export (QE they call it

So in the end, Apple is just guaranteeing a minimum flow (they aim at the loyal customers, not everyone, and those don't care about prices).
On my end, I don't care. I keep my MBP from 2010 and will do so until there is a 13 inch rMBA (or alike) and not that silver-space-gold piece of art they just released (though it is good... because that is the base of the new generation, and so it will become mainstream and cheaper

Maybe in 2016 or 2017.