Welcome to Health Reform Watch, Sarah Kliff’s regular look at how the Affordable Care Act is changing the American health-care system — and being changed by it. You can reach Sarah with questions, comments and suggestions here. Check back every Monday, Wednesday and Friday afternoon for the latest edition, and read previous columns here.

Days until marketplaces launch: 1!

Tuesday is the day! Three-and-a-half years have passed since the Affordable Care Act became law. A major Supreme Court case has happened, as has a presidential election. Babies that were not alive back then can now talk. The National Zoo has, in that time, lost a red panda, found a red panda and witnessed the birth of a giant panda cub. For pandas, this is a lot of activity over the course of 42 months!

(Courtney Janney, Smithsonian's National Zoo)

So, Oct. 1 has been a long time coming. It is the date when people can actually start signing up for the programs at the crux of the healthcare  overhaul. That makes it a bit disappointing to deliver this news: Most of the smart people I talk to expect Tuesday to be a bit of a dud.

We are not going to know, when Oct. 1 comes to an end how many people enrolled in Obamacare. And even if we did, that number would be unlikely to tell us anything about whether the law is a success or a failure. We just won't have that data on Oct. 2, and it will be months, some say even years, before we do.

Here's what you can expect Tuesday. The marketplaces will open at 8 a.m. in all 50 states and the District of Columbia, some run by the federal government and others by the state. The 34 federally-facilitated marketplaces will exist at www.healthcare.gov. Each state-based marketplace will have its own name and URL, like Cover Oregon or Kynect (that's for Kentucky).

Not everything will work perfectly on day one. Some states have already announced that certain functions won't launch until a few weeks from now. Here in the District, for example, anyone who wants to buy coverage with federal subsidies can do a bit of window shopping but won't actually be able to purchase until early November.

The states I've spoken with aren't planning really big rollout events Tuesday. Kevin Counihan at Health Access CT, who I spoke with for a story this weekend, isn't planning any events for Oct. 1.

"We're having a soft launch on this," he said. "Our next set of TV ads and the opening of our two retail stores is occurring in mid-October. It's not because we don't think we have anything to offer, we think there will be a lot. But we know we're going to have some bugs."

Mila Kofman, who runs the D.C. Health Benefit Link told me something similar. She contends that purchasing insurance is a big decision, one that you probably want to take a little while to decide on.

"I don’t encourage people to do any of this on day one because picking an insurance plan that’s right for you is a big decision," she says. "You need to talk to experts, so I’m really encouraging people to take advantage of the customer service we’re providing in October. But if you wanted to, October 1, you can do that."

In Oregon, the New York Times reports that the state has eschewed a flashy news conference or ads to mark its launch on Tuesday. “I have no idea what this thing’s going to look like on October 1,” Rocky King, executive director of Cover Oregon, told the paper. “We could crash and burn and have to close it down.”

A few states tell me they'll publish metrics on how many people visit their site on day one, but are unlikely to have enrollment data until later down the line. California, for example, has said it will release monthly enrollment reports. The White House has not set a timeline for when or how information about health law enrollment will be released to the public.

If you're an insurance shopper, buying coverage Tuesday doesn't make a ton of sense. Your policy won't start until January, but you will have to pay your first month's premium right away. There's no advantage to being first in line to sign up for health coverage.

The Congressional Budget Office expects 7 million people to enroll in the new marketplaces this year. There's not going to be a lot more that we know Oct. 2 about whether the White House can hit than goal, beyond what we know this very moment. Unfortunately, we're going to have to wait a good deal longer - until we have another grown up panda, even - to find out.

KLIFF NOTES: Top health policy reads from around the Web. 

There have been delays training Obamacare's in-person assisters. "Nonprofit groups and brokers that will help enroll consumers in the marketplaces, known as exchanges, say they haven't yet had a chance to preview the systems. Technical problems have limited certification for some nonprofit workers involved. And some of these groups say they haven't fully staffed up for the influx." Christopher Weaver, Timothy W. Martin and Louise Radnofsky in the Wall Street Journal.

Obamacare gets pitched at Kentucky's bourbon festival. "But potential buyers are wary.  On a late September night – just days before the Oct. 1 launch of the state’s online health insurance marketplace called Kynect -- most passersby are unaware of their new health insurance options under the law, confused by the political sniping and doubtful the law will help them. 'I thought this was defunded,' said Carolyn Richards, 53, of Mount Sherman, who has been uninsured for a decade. She had heard the Republican–controlled House of Representatives had voted to cut off the law’s funding last week, but was unaware that the White House and Senate Democrats were refusing to go along. Phil Galewitz in the Washington Post

Blue Cross Blue Shield Association will run Obamacare's multi-state plan. "The Obama administration plans on Monday to announce scores of new health insurance options to be offered to consumers around the country by the Blue Cross and Blue Shield Association and the United States Office of Personnel Management, the agency that arranges health benefits for federal employees, according to administration officials." Robert Pear in the New York Times