Stay in the home until you are contacted by the realtor that will be handling the REO representing the Bank (Seller), they will be the ones to make arrangements to vacate the home in a timely manner. Good Luck.
If you have a written lease, it remains in effect throughout the term. If you were on month-to-month tenancy, you may stay up to 60 days. You may be offered 'cash-for-keys' from the lender's rep or the new REO agent (since it just foreclosed on 04/28/11). Contact a tenant's right's organization right away -- early this week, to find out what your rights and obligations are as the tenant.