SAN FRANCISCO (MarketWatch) -- Some Americans likely will find their tax bills rising in about a year.

The George W. Bush-era tax cuts expire at the end of 2010 and the current outlook is that high-income Americans will take the brunt of the pain as income-tax and capital-gains rates revert to higher levels. But experts also say it's highly likely Congress will act to protect middle- and lower-income taxpayers.

"There are no facts about the future but if there were one it would be that the Bush tax cuts for the people below $200,000 a year are going to get extended, and the Bush tax cuts for singles above $200,000 and married couples above $250,000 are not going to get extended," said Clint Stretch, Washington-based managing principal of tax policy at Deloitte Tax, a consulting firm.

Others agreed -- with caveats. "The general sense has been that we are not going to have higher rates for anyone who doesn't make $250,000 or more," said Grace Allison, tax strategist with Northern Trust in Chicago.

"The problem that Congress is going to be up against is that extending the Bush tax cuts for lower- and middle-income taxpayers costs a little over $1 trillion over 10 years," Allison said. "So, basically, it's going to be a very interesting year."

That might be an understatement. In early 2010, President Obama's tax panel, headed by former Federal Reserve Chairman Paul Volcker, is expected to publish its ideas on possible reform strategies.

"That could form the basis for a major tax-reform proposal," said Mark Luscombe, a principal analyst with CCH Inc., a Riverwoods, Ill., tax publisher and unit of Wolters Kluwer. "Of course, we had a tax-reform panel during the Bush administration. It issued its report and it was ignored, so that's always a possibility."

More tax hikes -- and tax cuts

But wait, there's more -- at least for some taxpayers. Proposals to pay for health-care reform, should they come to pass, could bring even higher tax rates for high-income filers. In the House bill, for instance, there's 5.4% surtax on modified adjusted gross income in excess of $500,000 for single filers or $1 million for couples.

And, keep in mind: Some of Bush's tax cuts aren't done phasing in yet. While higher-income filers for years have been subject to a reduction (usually about 3%) in the value of their itemized deductions and personal exemptions, that hit has gotten progressively smaller in recent years, thanks to Bush's 2001 tax law. In 2010, higher-income individuals can take full advantage of itemized deductions and exemptions without facing that reduction. After 2010, that tax hit is back in full swing.

Meanwhile, a number of other tax perks are likely to be extended for 2010, including the deduction for state and local sales tax, the additional standard deduction for real property taxes, the deduction for tuition and educational expenses, and a deduction for teachers' classroom expenses. The House passed the Tax Extenders Act of 2009 on Dec. 9. Until the Senate acts, there's no guarantee what the final law will look like, but experts said those provisions will likely pass.

And the estate tax? It's likely lawmakers will enact legislation to make sure the tax doesn't disappear in 2010 as current law has it doing, experts said. The House passed a bill Dec. 3 that makes permanent the 2009 provisions: a top marginal rate of 45% on estates larger than $3.5 million or $7 million for married couples. Now it's up to the Senate to act. (Current law has the estate-tax rate reverting to a 55% levy on estates worth more than $1 million after 2010.)

Some are predicting Congress will enact a one-year extension of the 2009 law and then revisit the issue in 2010, CCH's Luscombe said.

Capital-gains rates set to rise

Lawmakers are likely to address the demise of the Bush-era income-tax cuts relatively early in the year, some say.

"Next year is an election year and I think it is not in their interests to have been unable to resolve tax cuts for the middle class going into the election," Stretch said. "The incumbents want to be able to go around the country talking about how they voted for a bill extending the tax cuts for middle-class taxpayers."

Right now, the marginal tax rates are 10%, 15%, 25%, 28%, 33% and 35%.

Obama and some Democrats propose to keep the lowest four rates, but let the highest two revert back to their pre-2001 levels of 36% and 39.6%.

If lawmakers do nothing, the tax rates would revert to their earlier levels of 15%, 28%, 31%, 36% and 39.6%.

The Bush legislation also brought a 15% tax rate on long-term capital gains and qualified dividends. And the rate drops to 0% for filers in the lowest two tax brackets.

Those rates, too, are set to expire at the end of 2010. Under current law, capital-gains rates would go back to 20% (10% for some lower-income filers) and qualified dividends would be taxed as ordinary income up to the top rate of 39.6%.

Obama proposes to levy capital-gains and dividend tax rates of 20% for taxpayers in the two highest income-tax brackets, and let the 15% and 0% rates continue for those in lower brackets.

Still, don't let tax law guide your investment decisions. "There's going to be a lot of excited talk about tax rates going up. People ought to engage their common sense before they go out and do a lot of stuff," Deloitte's Stretch said, adding that a 15% versus 20% rate on $10,000 is $500 of tax savings and "not a big deal."

However, if you're in a higher-income bracket, you'll probably want to avoid delaying income past 2010 if you don't need to. "You'd be deferring it into a higher tax rate if you're in those upper tax brackets," said Greg Rosica, Tampa, Fla.-based tax partner at Ernst & Young and co-author of the "The Ernst & Young Tax Guide."

"Conversely, deductions that you might be able to take in 2010 or 2011 might be much more valuable to you in 2011 because they'll offset a higher tax rate in 2011."

Alternative minimum tax

In previous years, lawmakers included a "patch" for the alternative minimum tax in their end-of-year extenders bill, but no such fix is in the current House version, likely because of the cost.

Because the AMT is not indexed to inflation, it needs an annual tweak to ensure millions more taxpayers don't fall prey to this parallel tax system.

Fixing the AMT "is very, very, very expensive and that is going to be one of the other issues that will come to the fore in 2010," Allison said. "What to do with the alternative minimum tax?"

Roth IRA conversion

A useful perk for high-income savers: Starting Jan. 1, there's no income limit on who can convert from a traditional to a Roth IRA. While there are good reasons to consider a Roth -- tax-free growth and beneficial inheritance rules among them -- proceed with caution.

For instance, if you don't have cash on hand to pay the income-tax bill that comes due when you pull out your IRA money, be careful. "Say you've got some other assets, but to convert to cash you have to pay capital gains, then [a conversion] becomes a less attractive option for you," said John H. Gin of Gin and Associates, an Ameriprise Private Wealth Advisory practice in Metairie, La.

Also, people in high-income-tax states should keep in mind that some state exemptions get phased out at higher income levels, Gin said. "A lot of these Roth conversion calculators don't take that into account."

If you do convert to a Roth in 2010, you can choose to pay half the taxes in 2011 and half in 2012 -- but opting to do it in 2010 may make more sense for higher-income taxpayers because of the likelihood of tax-rate increases in 2011.

Still, some advisers say Roth IRAs make sense for plenty of people. "That's an account that continues to grow tax-free and everything comes out of it, including the earnings, tax-free down the road," Rosica said.

Also, Roth IRAs "can be left to family members with much more favorable tax consequences as to when they have to start withdrawing than the traditional IRA," he said. "It's hard to give any kinds of rules of thumb on this one but particularly if it's a wealthier family that doesn't anticipate needing to draw from their IRA to fund retirement and intends to leave it to family members, this is probably a very attractive exercise for them to look at."