Kate will go, not necessarily because she wasn't good, but simply because she doesn't have the following of the other two. The executives at Sony/BMG are absolutely shitting themselves now that Lee looks like he might win.
Not too sure on Kate going. Her father is a local business owner (Toyota dealership) here in Bendigo, and word is out on the tens of thousands of dollars his business has spent on voting, not to mention the networking going on throughout Toyota in Australia. I don't doubt that she has her own legit fans, and having 2 hometowns behind you helps, but she shouldn't still be there.
I agree, if only because Kate seems imminently talented and Lee just keeps doing the same thing every week. Plus, Kate would be better suited to whatever Top 40 drivel the label churns out for her to do, while they'll struggle coming up with something for Lee to do.
I think he's the one who will end up with a career. And it would be better for Kate or Emily to actually come second, if the last two series are anything to go by.