UPDATE Wednesday: Read about the new Department of Labor work rules here and at the red links on that page.

Biggest change: bosses can't "exempt" workers from time-and-a-half pay, unless they make more than $913/week or $47,476/year. That's double the former limit of $455 a week. Takes effect Dec. 30 and will keep going up with inflation.

Result: employers who worked first-level managers and specialized workers hard will now have to pay them overtime after 40 hours a week -- or limit their hours. The government also says it's getting tougher on the use of "outside contractors" who are actually employees and should qualify for healthcare and other employer benefits. 

President Obama says the rule is "is expected to boost wages for workers by $12 billion over the next 10 years" for "4.2 million" American workers -- about 2% of the workforce.

But employer groups like the American Bankers Association complain employers may have to cut jobs or hours for some workers to comply, and will probably have more paperwork to prove they're not breaking the law.

TUESDAY: New labor rules pushing employers to pay overtime to all workers making under $47,500 (instead of calling them "exempt" managers, professionals, or even outside contractors), are expected in final form from Vice President Biden and Labor Secretary Thomas Perez when they visit Ohio on Wednesday, ten months after President Obama proposed them as a way to boost U.S. worker pay.

See Politico item on tomorrow's announcement here. read the Obama administration's original proposal from last summer here.

I wrote last fall about Vanguard Group citing the proposal among other factors when it busted 2,100 formerly "exempt" salaried workers down to hourly status, here and here. Some Vanguard workers told me at the time they feared the combination of hourly status, plus reductions in promotional raises and bonuses, would leave them earning less, instead of getting more as Obama proposed.

Christopher Mayer, partner at the Newark, N.J.-based law firm McCarter and English, calls the rules "big news," part of Obama's broader plan to use U.S. Labor Department rules and enforcement to increase net pay and wage levels. Companies will have to track workers' hours more closely to make sure they comply.

Mayer says DoL and the Internal Revenue Service have also stepped up investigations of independent contracting arrangements. "Contractor misclassification" costs state and U.S. treasuries a lot of money, he told me. "If the Department of Labor and the IRS determine that an independent contractor is really an employee, they may become subject to to the Fair Labor Standards Act" and the stricter new overtime rules.

Companies like Comcast, with its thousands of contract workers, could be affected on multiple levels. Not just installers -- some layers of Comcast managers at call centers and other teams and groups -- may come under the rules, Mayer said.

Information technology consulting firms will have to similarly review and, maybe, reclassify many service people as fulltime employees with overtime rights, Mayer added. That could mean big changes for the fiscal calculation on whether to provide services in-house or through outside companies.

The rule could have its biggest impact on low-wage Southern and Midwestern markets, Mayer added, and among retail, warehouse, hotel and hospitality, branch banking and nonprofit employers who typically pay low wages.

He expects companies will have 60 to 90 days to implement new policies. While the administration's goal was announced years ago and the rules well in advance, Mayer says he expects many employers still aren't ready, and there could be a political reaction.

As at Vanguard, some companies may react -- instead of boosting net pay, as Obama envisions -- by taking steps that threaten to cut workers' take-home pay. Mayer warned that can be a disruptive course for any company to take, especially as wages are finally starting to rise, seven years after the last recession. Some companies, he concluded, have a lot of training ahead.