If they do release it as a single, expect it to be released in December.
If you are a PSB fan, you might remember that when they released Discography, there were 2 news singles on it: DJ Culture and Was It Worth It.
They released both of them, but Was It Worth It later.
I somehow expect Turn to be the bridge between WFTSC and the next single from the 2006 album...
But that's just a theory...