I had this problem, went to the genius bar and was quickly offered to replace the defective component for free in under a week, if I remember correctly.

It's still much too long to go without a computer, but it's worth it when you realise you've been coding for three hours and haven't lost a single line of code to a crash.

That being said, before I got the part replaced, upgrading to... was it snow leopard? the latest version of OS X, anyway, increased the frequency of the issue by rather a lot. So, possibly, hold off on your update?