According to the column, an episode of Smallville will take place on an alternate earth, and when asked whether this alternate earth was different from what we saw in "Homecoming," Kristin wrote, "It is. We can also tell you that the Clark in this 'alt Earth' has been raised by someone other than the Kents, and it makes him veeerrry different and very interesting!"
Not too difficult to figure this one out. It's well known that John Glover is going to be reprising his role of Lionel Luthor, so undoubtedly that "someone other than the Kents" is going to be Lionel, which means that the Clark of that world is going to be VERY different and far more ruthless.