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Two months after it first launched, the troubled Obamacare insurance portal HealthCare.gov is supposed to be back on track today, according to the Department of Health and Human Services. It's a major moment for the beleaguered White House and the millions of Americans hoping to sign up.

Here's where things stand and what to look for:

THE DEADLINE

President Obama and top administration officials have repeatedly promised that the website will be "optimally functional" for the "vast majority of users" by the end of the day, Nov. 30, two months after it first launched. Technical teams have been working around the clock through the holiday on last-minute hardware and software fixes. Administration officials say that people will now be able to smoothly navigate the online process from start to finish: registering for an account, completing an application, obtaining a subsidy eligibility determination, comparing prices/plans, and formally enrolling.

The White House has been deliberately vague about how success will be measured, however. They have given no official metrics to define "vast majority" or "optimal functionality." It's up to you to decide.

WHAT TO EXPECT TODAY

NO 'MISSION ACCOMPLISHED' MOMENT: Centers for Medicare and Medicaid Services officials who are managing the site won't declare victory today, and the White House has told its health care allies (Enroll America, SEIU, et al.) not to trumpet the newly-repaired site.

The self-imposed deadline is expected to pass without fanfare, a deliberate strategy aimed at keeping public expectations in check and avoiding heavy traffic that could precipitate another embarrassing crash.

There will be no major re-boot or re-launch of the website, per CMS. It will appear on the surface as it has for the past few weeks. Administration officials say they will gradually re-ramp-up an enrollment campaign as confidence in the site grows.

AT HEALTHCARE.GOV: Compared with the user experience on Oct. 1, the website is already vastly improved. Consumers can now register and create an account without much difficulty. Navigating between pages happens in milliseconds, down from the sluggish 8-second response time observed in October. The error rate for applications has dropped from 6 percent to a fraction of 1 percent. Officials say the site will now be able to handle 50,000 concurrent users - its original intended capacity - and up to 800,000 unique visitors per day.

CAVEATS: The administration says peak periods (2 p.m. being the pinnacle) could still be problematic for some users to log on. Starting this weekend, a new queuing system will go online to moderate the flow of traffic into the site and help avoid congestion. If there are more than 50,000 users trying to shop, people will be redirected to a waiting room, notified of the wait time and allowed to get notification by email of when to come back.

Meanwhile, officials will not guarantee that the site won't crash again under the weight of heavy volume. In the early days of October, it was getting crushed with 250,000 simultaneous visitors - a capacity it still cannot handle. The site has recently experienced unscheduled outages under very little traffic, with several occurring in the past week. It is "important to understand that [the website] will not, from time to time, work as it should," said CMS spokeswoman Julie Bataille. "Unscheduled outages may continue."

WHAT'S AT STAKE

The effective re-launch of HealthCare.gov is a high-stakes PR moment for the White House and Democrats. The administration wants to put to rest a tumultuous period of technical glitches and capacity problems that have dominated headlines, frustrated consumers, energized Republicans and devastated President Obama's poll numbers. Congressional Democrats are particularly anxious to have the issues resolved as the 2014 midterm campaign begins to heat up.

What may matter most in the next few weeks is whether the public sees the fixes as adequate and thinks the user experience has sufficiently improved. Meanwhile, insurers say they need the system to start processing more enrollees, and pronto, particularly the young and healthy. Insurers have warned that a disproportionate number of older and sick enrollees - and far fewer overall sign-ups than the 7 million originally projected - could have an adverse impact on 2015 premiums.

RACE TO SIGN UP: THE NEXT DEADLINE IS DEC. 23

Americans who want to purchase an Obamacare plan that takes effect on Jan. 1 have just three weeks left to sign up. Applications must be completed and plans selected by Dec. 23 rd, according to the latest guidelines from CMS. The first premium is due to an insurer by the end of the year. For everyone else currently without an insurance plan for 2014, the deadline to sign up is March 31. That's when the individual mandate will start being enforced.

THE LATEST ENROLLMENT NUMBERS

More than 200,000 Americans have signed up for health insurance through one of the new Obamacare exchanges (state and federal) through mid-November, according to a Commonwealth Fund analysis of publicly available data. This is more than double the total that signed up in all of October. Many states have been reporting a surge in sign-ups over the past few weeks. Health and Human Services won't release an update on overall or federal enrollment numbers until mid-December.

Overall, through mid-November, "enrollment" is only at about 2.9 percent of the CBO projected target of 7 million Americans to sign up for 2014.

NO DELAY FOR INDIVIDUAL MANDATE

Despite a flurry of announced delays for key components of Obamacare over the past few weeks and months, one major and controversial piece is still on track to take effect at the end of this year - the individual mandate. Administration officials have told ABC News the website's technical woes will not impact that deadline of Jan. 1, 2014, though they have previously clarified that the mandate's penalty won't be enforced until Mar. 31, 2014, the end of the open-enrollment period.

In case you haven't been keeping score at home, here are a few major provisions that have been delayed:

- Business Mandate (requirement that companies with 50 employees or more offer insurance or pay fines): Delayed one year, from Jan. 1, 2014, to Jan. 1, 2015.

- Online Enrollment for Small Businesses: Delayed for one year and one month, from Oct. 1, 2013, to Nov. 1, 2014.

- Sign-Up Deadline for January Obamacare Coverage: Delayed one week, from Dec. 15, 2013, to Dec. 23, 2013.

- 2015 Open Enrollment: Delayed one month until after the midterm elections, from Oct. 15, 2014, to Nov. 15, 2014.