Just breaking:

Sen. Barack Obama tells USA TODAY's Kathy Kiely that he has chosen a running mate, but the presumptive Democratic presidential nominee wouldn't say when he made the decision or when he will reveal that person's identity.

"I won't comment on anything else until I introduce our running mate to the world," he says. "That's all you're going to get out of me."

So, um, we'll just keep waiting, I guess.