Can A Will Be a Contract? Can you Breach a Will?

In the already interesting case of the now deceased Dr. Ivins, accused by the FBI of being the anthrax killer, it is now reported that Dr. Ivins left an unusual will.  In essence, the will provided gifts, subject to proof that his family disposed of his remains in accordance with his wishes.  If not, most of the assets go to Planned Parenthood.  

Is This a Contract? Or a Will?

According to a New York Times story, both following his instructions about disposing of his ashes and giving money to Planned Parenthood conflict with his wife's religious beliefs.  So she has a choice. This looks a lot like a unilateral contract.  If you will do X, I will pay you Y.  

Can the wife "breach the Will" and still take the money?  Apparently not!  Is the bequest unconscionable?  Doubtful!  What happens if the wife dissipates all the assets paying legal fees to try to clear her husband?

Which choice will the widow make?  I'm sure there will be more on this unusual story.