In 2009 a law was passed that through the end of 2014 the bank must honor existing leases up to a maximum of 90 days after foreclosure. In your case, you have a month to month, so they must give you a months notice to move out. Here is the link to the law:
http://www.occ.gov/publications/publ...dbook/ptfa.pdf
If the old landlord files you on his bankruptsy, you may not get the deposit back. I would ask him to send it to you now or if you could simply skip a months rent, since he will not own the property when you move out.