Let me clarify by saying that it's not necessarily a bad thing that they are there, rather very surprising knowing what cornerstone is usually like: everything that creation and kingdom bound aren't.
I think Cornerstone tries to bring in a few big name CCMers each year so they can draw a large crowd. Only so many people will come for the more obscure stuff, but they can get a huge response by bringing in the pop artists.
Or at least that's my best theory as to why Newsboys and Jeremy Camp were considered headliners last year. Kutless becoming a regular is a bit scary as well.
I actually like a good deal of CCM, so i'll probably see at least one or two of those bands. I won't be sold on having to go until they put Over the Rhine on there though.