Is it correct to assume that the home was sold at a trustee's sale and that's why your old landlord no longer owns it? If that's the case, the lender may have contacted the owner to ask his assistance in trying to vacate the property, but if you're in a lease you have protections. I can't imagine any claim you might have against the landlord, but if you feel you have rights I'd contact an attorney experience in real estate and foreclosures. That said, I'm pretty sure new legislation passed in May of 2009 allows you to stay until the end of your long-term lease and/or 90 days minimum if you're on a month-to-month lease. Your monthly rent should be paid to the lender once they contact you.
As a side note, were you paying rent over the last year? If you were, it's likely the loan documents indicate he should have been forwarding all of it to the lender. Many landlords do not do so and could be held liable by the lender (if they choose to pursue it).
I also wanted to correct Michael's response since he's probably answered based on Minnesota foreclosure guidelines instead of California's. They're different, and that's why local agent knowledge is so important on this site!
A former owner's right of redemption in California is complicated. Lenders usually pursue a non-judicial foreclosure which means a maximum of one year is possible, but that's limited to 3 months if the lender makes a full price bid at the trustee sale. Beyond that, if the lender waives their right to a deficiency judgement (meaning they choose not to pursue the borrower for the money they are owed), there may be no redemption period at all. Specific situations including judicial foreclosure alter these guidelines. Anyone facing foreclosure should speak with an attorney qualified to advise on real estate, foreclosures, and possibly bankruptcy.
I suggest you try to contact the lender directly to see what their plans are, and then follow up with local experts as necessary.
If the home has been foreclosed, depending on the circumstances, the homeowner has up to 6 months to redeem the property from the bank. Technically in this period the homeowner still owns the home. Only after the expiration of the redemption period does the bank own the home.