Don't try and replace a really strong cast member! Create a new dynamic with a different character. And her being a woman is not different enough!

I don't actually think this is what they're trying to do--I actually think what they're going for is continuity. Because if Lex did mysteriously vanish, there would have been some response from Luthercorp. And I kind of like the idea that Lex has built up Luthorcorp to the point that it will continue despite his absence (since we know that he can't be dead). I want to see what they'll do with Tess, but I'm not immediately opposed to her.