What happens if the The Dollar is abandoned and new currency issued?

An interesting question and a rather extreme scenario I suppose.

As you indicate, the currency can suffer quite a bit of damage through either inflation or deflation.

I am not sure, however, how the contractual obligations would be affected in an insurance or annuity contract if the currency were replaced. 

I suppose it depends on the wording in any given contract.  I'm just not sure whether contracts would address this potential yet extreme scenario.

We will be interviewing a company that is involved in the Swiss annuity market this coming week.  Annuity payments are made with the Swiss currency rather than the U.S. dollar.

We will present the question to them, so keep an eye out for the interview.