I see some people chiming in here saying things like, "I've got a PhD. It's just statistics. Definitely not sentient." I recognize this sort of comment as basically saying, "There's nothing fundamentally different about how these things work that makes them somehow special." And yes, I agree.
But how does this disprove sentience? It doesn't. Maybe this is more of a nitpick and doesn't really matter. After all, I don't personally believe these programs are sentient. But given our limited (non-existent?) understanding of consciousness, this can only be my belief and nothing more.
Maybe this distinction will be more important in the future when we're closer to the brink.