13.11982404 BTC, lost forever...
plus another 55.55748666 BTC, lost forever...
Yea, you know what would suck? If a major charity organization launch a campaign for say, Cancer and they type the donation address incorrectly in a advertisement or on their webpage and then millions of dollars goes into the wrong address, before they notice it.
We see human errors every day with data capturing or typing, so it is not impossible that this might happen in the future.