His campaign has sent out a very cryptic press release promising a news conference tomorrow, with Elizabeth, in North Carolina. He was scheduled to be in NYC tomorrow. Additionally, he missed a campaign appearance earlier this week to attend a doctor's appointment with Elizabeth. I'm hearing rumblings that he may drop out.
Update: I am, happily, hearing more contradictory things now, as the campaign is apparently telling folks not to assume the worst. There's not much reason for them to do that if they are announcing a definite end. But, for now, we really just don't know. Hoping for the best is all we've got, and I, for one, am hoping.