It is impossible to know what Congress will do with the Estate & Gift Tax laws for years 2010 and beyond.
I am concerned that if a person dies in 2010 before Congress acts. If your documents provide that all of your property in excess of the maximum exemption equivalent passes to your spouse, there could be a period of time in 2010 when all of a deceased spouse's property passes to his or her spouse. Then, if Congress brings back the federal death tax, the first spouse's exemption might be wasted!
SOLUTION: I am attending the Heckerling Institute January 25-30, 2010. I hope to learn if there are any proposed solutions to this problem.
In the meantime, a family might consider an amendment to their documents that would remain in place until Congress acts.