death and ($600 million less in) taxes: the case of George Steinbrenner

From Laura Saunders in the WSJ...

The timing of George Steinbrenner's death (in 2010) will probably save his heirs a ton of money in taxes.

The Yankees owner accumulated a net worth of about $1.15 billion, according to Forbes magazine—much of that stemming from the YES television network. Mr. Steinbrenner acquired the Yankees in 1973 for $10 million.

Because Mr. Steinbrenner died in a year when there is no federal estate tax, he potentially saved his heirs a 55% levy on his assets—amounting to a tax bill of about $600 million.

The 55% tax takes effect on Jan. 1, 2011.

If Mr. Steinbrenner had died in 2009, when the estate-tax rate was 45%, his estate-tax bill could have been nearer $500 million....

Two obvious angles come to mind:

1.) Why is there an estate tax in any case? Steinbrenner has already paid taxes at least once-- on all of that money. (If the money was earned illegally, then perhaps not; on the other hand, he's probably paid taxes on a lot of money more than once.)

2.) If Congress is going to have an estate tax, why have 45% last year, 55% next year, and 0% this year?!