Congress = Uncertainty Inc.

One of the expiring tax credits Congress has backburnered allows companies to more quickly write off their equipment investments and reduce their tax bills.

NEW YORK (CNNMoney) -- House Republicans say the two-month payroll tax cut extension passed overwhelmingly by the Senate would inject uncertainty into the economy.

"A two-month extension creates uncertainty and will cause problems for people who are trying to create jobs in the private sector," House Speaker John Boehner said Monday.

But no matter how lawmakers resolve the impasse, Congress has already injected plenty of confusion into the lives of ordinary Americans and businesses.

For starters, Congress' inability to move coherently on the payroll tax cut "reinforces the very deep feeling of uncertainty people have that Congress can't even do the simple stuff," said Clint Stretch, managing principal of federal tax policy at Deloitte Tax.

Payroll tax: What a mess

And while the payroll tax cut, which would affect 160 million people, is garnering all the attention, dozens of other soon-to-expire tax breaks have thus far been largely ignored by Congress.

One of them allows businesses to accelerate their depreciation on equipment purchases.

That tax break can be a big help to cash-strapped small businesses: It lets them more quickly write off their investments and reduce their tax bills, Stretch said.

Max Baucus, the lead senator on tax policy, said in a statement over the weekend that his Finance Committee will "keep fighting" to extend the other tax cuts in January.

The goal, he said, is to act early in the year to maximize the tax break extensions' effect and provide certainty.

Well, that may work. But in some respects, it may be a little late.

Peter Boockvar, chief market strategist with Miller Taback & Co., told CNNMoney that recent signs of strength in the manufacturing sector, including an uptick in new orders for durable goods, may have stemmed from businesses rushing to take advantage of the so-called bonus depreciation before it expires.

Payroll tax cut: What's at stake

That could lead to less business spending than otherwise would be the case in the first quarter of next year.

And even if companies remain confident that some of the staple business tax breaks -- such as the research and development credit -- will be extended eventually, they may not be able to benefit quickly, Stretch said.

Why? Because if a company has to file a quarterly financial statement before a given tax break is extended, it won't be able to reflect the value of that break on the statement.

--CNNMoney's Ben Rooney contributed to this report.