So upon further investigation, it totally seems like there is a Photo Booth bug that started on the 27th of December, 2009. Starting around then, all the files it saves have the year 2010 instead of 2009. This is pretty bizarre. It looks like after 12-27-2009, Photo Booth always thinks it is one year in the future.
Might only impact Snow Leopard… my sister is unable to reproduce, but she’s still running Leopard. Or maybe it’s just my house. Yes, my system time is correct. =p