Not much time left, so I figure people should be allowed to guess the same day as other people. More like a probability chart.

My guess is the obvious one, the Friday before the Hard Assets Show - May 9. There might also be a halt on Thursday May 8 to accomodate releasing the NR.

That said, their strategy could also be to talk up KXL at the show, let some people get in, and then goose it with good data.