Microsoft today admitted to an "unacceptable number of repairs" (source) for the Xbox 360, announcing it would take a $1 billion charge due to the repairs.

Because of this situation, Microsoft has done the right thing...
The company said it would extend warranty coverage to three years to cover the problem and would reimburse customers who had previously paid for repairs related to the three-flashing-lights error message. It also said it has made improvements to the Xbox 360 console.
Despite the $1 billion charge, and missing shipping expectations (11.6 million vs. 12 million), MS says it still expects to be in the black for fiscal year '08, which I believe, would be the first time the Xbox division is profitable for a full year.
Job well done, MS. Unlike many other technology companies, you've admitted to your mistake, said you'd fix the machines for free and extended the warranty to 3 years, which is one of the longest warranties for any consumer electronics product. This will help to maintain confidence in the product and will help with sales.
If your Xbox 360 has gotten the red ring of death, you can try the towel wrapping method before sending it in.