Facebook have, for years now, not really been deleting your photos. Yes, they may not be on your profile (or Timeline) but they would be enjoying some cocktails somewhere in the social networking sites content network for months, if not years.
Ars Technica, after some experiments, have reported that this problem should now be over. Instead of the months-long photo storage system migration and now an updated deletion policy, Facebook will now only let photos stay on their content network stream for no more than 30 days.
After this, they're deleted, permanently. This is an improved reaction speed, at 30 days, but still isn't as good as a 'click, delete, gone' method such as other photo-sharing services. I supposed you can't really complain, it's better than them changing your news feed look, again.