Holy freaking boatload of posts "emvchip" - wow.
Anyway, what's your "understanding" of Chase's chip and PIN plan based upon? Given it was announced after Target talked, it sounded at least semi-likely to be real chip and PIN cards.
Why do you say the Diner's Club doesn't allow signature? Is that based on the CVM list or on speculation? How many terminals in the world really don't support PIN?
Agreed humans are unpredictable, though today at Walmart at a register the chip failed at they made me use a different lane rather than let me try it until it let me swipe (said, oh you can't use a chip card in this lane). That was a simple "card problem" error.
In the next lane, I again had the issue I've been having with my Delta Gold Amex where it takes a few tries to go through...