What follows is my understanding of estate taxation. Since this is not my "first line" of business, I would appreciate corrections.
Based on the current rules, there is no federal estate tax for decedents passing in 2010.
There may be, however, a capital gains tax. Previously, appreciated assets like stocks, real estate and so forth received a stepped-up value so that when the asset is sold, the new owner would have a tax basis equal to the value as of the previous owner's death or an alternative value 6 months later. That step-up has ended, and when sold those assets now will be taxed at capital gains rates using the original owner's basis.
The two exceptions to this new tax are a $1.3M exemption on the estate, and an additional $3M exemption for a surviving spouse.
Any errors or additions?