As tenants you are in a very favorable position. Read up on legislation passed by Obama in May of 09. In summary, present your lease to the new owner of the home. Mostly you can work out a deal. As long as you pay your rent to the new owner then they have to abide by the lease. I forgot if they have to abide by it for the duration of the lease or not, check with an attorney. If you stop paying they can go through the formal eviction process. If the home does foreclose you will get people coming by to scope the home out the day before the sale. Let them know you are the tenants. If I were you I would try to score some money out of it by asking them for cash in exchange for keys.
Get the best of both worlds and make some money out of your landlords misfortune. In all likelihood the foreclosure will get postponed.
Now as to whether you should continue to pay the current landlord rent in the event of a postponement… well that is your issue to deal with.