Now MAC is forced to recall laptop batteries due to a potential fire hazard. I have two batteries that are affected. Here's the info from the apple website:

Q. How long will it take to receive a replacement battery from Apple?

A. It may take up to 4 to 6 weeks for your replacement battery to arrive. Shipping time may vary due to availability of your battery model.

Q. Can I use my computer without the battery in it?

A. Yes, once you've removed the affected battery, just plug in the AC adapter to power the computer until a replacement battery arrives.

Funny thing is, I purchased the extra battery because the original was getting hot. The "genius" at the apple store told me it must have gone bad and I needed to replace it.