The new 2001 Tax Act was supposed to be historic; mainly, however, it is turning out to be hysterical-as in very funny.

The new law is jammed with all sorts of cockamamie provisions and legislative gimmicks, most of which are foolish, offensive or just plain dumb. At times, the legislation is so goofy that you suspect Congress is playing an intentional prank: Puck must definitely have gotten his hands on the Internal Revenue Code. This is a Mid-Summer Night's Tax Law.

The first tip-off about our jester Congress is the provision stating that the entire new law-every single word-is supposed to disappear on December 31, 2010. Congress, in the past, has put transition rules in tax legislation to provide a shifting from one set of tax rules to another. But this is the first time that Congress has passed what amounts to a "transition tax law." Basically, Congress wants to lower tax rates, abolish the estate tax and commit all kinds of fiscal mischief over the next 10 years-and then come back to where we are today. A pretty good description of this process is called walking in a circle.

The so-called "massive" income tax cuts touted by various politicians are in fact a series of modest marginal-rate reductions phased in slowly over six years. Then, after 10 years, the cuts are repealed, and we are back where we started.

On the estate tax side, meanwhile, the legislation is the equivalent of one of those stun grenades used for crowd control-a huge flash, a deathly roar, lots of smoke, but then almost nothing happens. The act supposedly abolished the estate tax. Yeah, right. What it really does, over a period of nine years, is bring the maximum tax rate on estates slowly downward, from 55% in 2001 to 45% in 2009, while raising the unified credit (the portion of an estate exempt from tax) from the current $675,000 up to $2 million in 2008, with a last-gasp bump to $3.5 million in 2009. Then, in 2010, there is a complete abolition and repeal of the estate tax (hurray!), followed by a repeal of this estate tax repeal, effective January 1, 2011, thereby pushing the estate tax back up to 55% and the unified credit back to $1 million.

Huh?

If you are befuddled by all this chicanery, then welcome to the club. Until 2010, the new law doesn't abolish the estate tax at all, and in fact barely does more than index the estate tax for a quarter of a century of inflation since the last major estate tax overhaul. Bear in mind that the unified credit was set at the equivalent of $600,000 in 1981, and today, 20 years later, it is up to just $675,000. Bumping the unified credit to $2 million, or even $3.5 million, barely covers the cumulative inflation since the Reagan administration.

For sheer hilarity, however, you can't beat a law that abruptly abolishes the estate tax for just one calendar year (2010) and then reinstates a 55% estate tax on January 1, 2011. This perverse rule has been referred to sardonically as the "Throw Momma From the Train" provision-every child in America with wealthy, aging parents will face unmentionable temptations during the year 2010.

Meanwhile, for families in the upper-middle class or "poor rich" stratums, the year that momma needs to watch out for the kids is actually 2009. That's the year that the unified credit jumps to $3.5 million (i.e., that much can pass to heirs tax-free), plus, there is still a full step-up in tax basis in inherited assets. This means that if momma, that thrifty soul, owns a portfolio of stocks worth $3.5 million and has low tax basis in her stock, the kids can inherit the full $3.5 million free of estate tax and avoid future income tax liabilities on the later sale of those stocks-but only if 2009 is the year that momma takes her, er, train ride.

Families with a lot more than $3.5 million, meanwhile, are probably better off deferring the train ride until 2010. However, there is a trade-off: Coupled with the repeal of the estate tax comes the repeal of the step-up in the tax basis of assets on death. This means that while heirs in 2010 will receive assets free of estate tax, those assets come with built-inincome taxliabilities. Moreover, to make sure that parents don't erode the income tax base by making gifts of income-producing property to children, the estate and gift taxes are no longer unified starting in 2002. This means that momma could still pay a hefty gift tax for lifetime property transfers, even though there is no longer an estate tax on death.

Most people think that the new law will give momma every possible incentive to hoard her wealth to the very end of her days. By 2010, momma should be rich, paranoid and living in a fortress-and she definitely isn't going on any train rides with the family.

Then, on January 1, 2011, the repeal of the estate tax will be repealed automatically (unless, of course, the repeal of the repeal is repealed, but I digress ...), and we will be right back to where we are today. Sort of.

In fact, the likelihood that the estate tax actually will ever be repealed in 2010 is absurdly low-about the same odds as our ever getting a sensible, well-crafted tax bill out of Congress. The estate-tax rate edges modestly downward, and the unified credit appropriately upward, to a pretty fair level by 2009. By then, the political winds will have shifted 10 or 15 times at least, and who knows what will happen after that.

Meanwhile, everyone understands that the dopey provision to repeal the entire tax act in 2011 is merely some legislative legerdemain designed to circumvent an arcane budgetary procedural rule called for by the Byrd Amendment.

Basically, the Republicans needed 60 votes to cut taxes for a period of greater than 10 years, so they went as far out as they could go, got a meaningful tax cut, and called it a day. Score one for the elephants.

Meanwhile, the alleged "repeal" of the estate tax is a political win-win: The Republicans can claim they honored their repeal pledge, and the Democrats can take comfort in the fact that the estate tax really stays exactly the same (with only a long overdue inflation adjustment) through the next two presidential elections. The only losers are the taxpayers, who are being conned and mislead by all the hoopla surrounding the illusory "repeal."

Of course, there is always a slim possibility that the estate tax repeal might one day go into effect. If so, Congress had better fix the insanely tangled carryover basis rules: These rules are so complicated, and so thoroughly unworkable, that the estate tax actually is a BETTER alternative.

Among other things, the post-repeal rules would mean that 1) taxpayers suddenly are trying to put the highest possible value on estate assets, instead of the lowest (valuation experts for taxpayers and the IRS would have to switch jobs), and 2) because of rules to allocate the unified credit on death to create a tax basis in estate assets, kids would start giving highly appreciated assets to their elderly parents.

When all is said and done, the signing of the new tax act is not the beginning of the end for the various repealed taxes, but more likely the end of the beginning. The reality is that this act, with its endless phase-ins, constant adjustments and uncertain impacts, is all but guaranteed to trigger many more rounds of political wrangling. In the meantime, the tax law is a tangled mess, no one knows for sure what to do about tax planning, and chaos reigns supreme. Puck-the fictional character-expresses perfectly the inevitable consequence of human vanity and foible: "Lord, what fools these mortals be."

And Puck was not even talking about Congress.

Joseph B. Darby III is chairman of the tax department in the Boston office of the international law firm Greenberg Traurig LLP.