That's Karl on the left. Eternity on the right.
I love Melissa, but don't tell her. It's a secret if she can find this. Shhhhh....
This has been suggested before, but seems to be too difficult to implement accurately. "In print" is a subjective term and is affected by geographical variations. Really, any game is Out of Print as soon as its batch has left the printers. Some Out of Print games can still be found in shops, if you look carefully.
It would be something useful to implement though.
Perhaps if we defined "in print" as "Publisher still has copies". Once the publisher runs out, it's get them if you can still find them time.