Apple won't care.
It has $146 billion in cash on its balance sheet.
The $500 million sum is almost ironic — it includes triple damages for consumer injury. The tripling is supposed to deter companies from fixing prices by making it very expensive if they get caught. But the tech business is so much bigger than the book business that even triple damages aren't a deterrent.
That diminutive penalty also explains why all the other publishers settled the case for a mere $166 million collectively, and why Apple chose to fight on. Its financial risk was not significant to give up the chance of winning.
(Apple may also have believed it had a case. After all, it can argue that all it did was provide greater access to ebooks for more customers at a price that was above Amazon's $9.99 setting. Neither publishers nor readers were forced to take the deal.)
GigaOm made this handy chart that shows how Apple's damages might be calculated: