Stephen J. Entin (President, Institute for Research on the Economics of Taxation) has published The High Marginal Cost of the Estate Tax:

The estate tax is not yet dead, by a long shot. Federal taxes on estates fell as a result of the Economic Growth and Tax Relief Reconciliation Act of 2001 (EGTRRA). In fact, the estate tax will even disappear for one year (2010) due to EGTRRA. In 2011, it is scheduled to return with a higher tax rate and lower exemption than before. However, Congress is expected to pass legislation applying the tax retroactively to those who die in 2010.

There are a number of reasons to permanently repeal the estate tax, including the economic damage it does, the fact that it doesn't raise any net revenue and the confiscatory tax rate it can impose, at the margin – even on middle class taxpayers. …

The economy, the pretax and post-tax incomes of workers, savers, and investors, and federal, state, and local revenue would all be higher if the estate tax was eliminated.