One result of President Reagan's tax-cut bill is that millions of prosperous Americans need to have their wills examined and redrawn.

So there is joy today in New Orleans, where the estate lawyers of America, the ones who get paid to do the examining the redrafting, are meeting as part of the annual convention of the American Bar Association.

These lawyers and other tax lawyers anticipate a flood of business, so much that one of them suggested to the group today that they hire law students to help them handle it all.

"We will tell them [the clients] that they ought to try to live as long as possible," joked Johannes Krahmer, a Delaware estate lawyer and vice chairman of the estate and gift tax committee meeting here, "at least until all the benefits of the bill are completely phased in."

But among the estate lawyers, at least, the joy is tinged with some concern about their future. Some speculated that the same bill that will help thim financially in their law practices over the next few years may ultimatley render some of them obsolete.

"Maybe we ought to think aobut getting into corporate or product liability law," one member of the committee told the group. "There are too many of us in this field already."

Such are the rionies of the 1981 tax bill. While legal services lawyers may be looking for work next year, others will be trying desperately to handle all the business generated by the legislation.

Any revision in the tax laws, whether it benefits or hurts various classes of taxpayers, tends always to benefit tax lawyers. They are the only ones who really follow what happened, but this time they don't pretend to understand it all.

But they do understand the provision virtually eliminating the federal estate tax for millions of americans. Before the bill, the Internal Revenue Service imposes heavy taxes on all of a deceased person's property worth more than about $175,000. After the new tax law takes effect, that figure will rise by 1986 to about $600,000.

The percentage of taxpayers filing estate tax returns (and hiring lawyers to help them sort it out) will fall from about 3 percent of all taxpayers to about one-third of 1 percent, the lawyers said today. Such numbers don't sound significant, but they involve millions of taxpayers.

That fact, in turn, has its own multiplier effect. Philadelphia estate lawyer John B. Huff speculated that the "big losers" from the estate tax revision may be life insurance companies. He said that many of the six-figure insurance policies are purchased to help survivors pay the inheritance tax.

"Now," he said, "you take a half-million-dollar estate and you can forget completely" about the federal taxes and perhaps the six-figure life insurance policy. "The insurance companies," he said, "are going to lose like mad."

The heavy estate taxes that will become a thing of the past for some have also tended to control how people dispose of their wealth, the lawyer said. "The tax tail has been wagging the dog," Huff said. "This bill lets people think more about how the money should really be used" than about what must be done to account for the heavy taxes.

"It actually does a lot for ordinary everyday fold," said Doris Blazek, who heads the ABA committee. "It brought the law into line with the way people live and with what they believe," she said. "They believe that it is their money."

Two other important provisions were discussed today by the tax lawyers. One allows spouses to pass on wealth to their husbands or wives even beyond the $600,000 level without paying any taxes. The other increases the maximum gift that can be given without facing tax liability from $3,000 to $10,000.

"None of us has thought through the full implications of all these changes," Blazek told her committee. "There's going to be things coming out of the woodwork for a long time to come."

"Yeah," said someone from the audience, "I don't expect anything to stay the same for more than three years."

"That's right," responded Blazek. "Grab the goodies while you can."

Blazek said she did not share the concern of some of her colleagues that nobody will need them in a few years. Some of the lawyers suggested that other parts of the Reagan taxcut bill might be so inflationary that $600,000 may not be so much after awhile.

In addition, congresses and administrations come and go, and new laws could change the situation.

In the meantime, these lawyers will be enjoying the fruits of the current administration. "We gotta tell them [our clients] that they have until the first of the year to change their wills," someone in the audience said, "so they don't all come in at once and spoil our Labor Day."