Last year, during the disastrous rollout of Healthcare.gov, many conservatives were gleefully predicting doom for the law as a whole. The exchange websites wouldn't work, nobody would sign up, nobody would pay their premiums, and only sick people would get coverage, leading to a death spiral of rising prices.
A year later, Aaron Carroll checks in with these predictions. It turns out that since the government managed to get the website on its feet, none of them have panned out. The administration is beating its coverage targets, and plans are cheaper on average than initially predicted. Overall, things are going well (though states that refused the Medicaid expansion have done themselves stupendous damage).
Two notes for the future. First, lots of people are still eligible for Medicaid but haven't signed up. Second, open enrollment for ObamaCare is from November 15th to February 15th, and everyone who has coverage through the exchanges should check their options again, because there might be a cheaper or better option available. Both those things are available on Healthcare.gov. --Ryan Cooper