Since the switch from ATI to NVIDIA GPUs in the MacBook line, Apple has had an uncharacteristic number of support issues, ranging from overheating to failing displays. The last major problem was acknowledged in October 2008, when NVIDIA put out a seemingly large number of faulty chips, and had to spend $200 million to appease the quality police. In fact, my last MacBook Pro fell victim to the problem, and the logic board failed twice, and Apple had to replace it with one of the new unibody models (yay). Unfortunately, the problem, which was attributed to the 8600M GT processor, has resurfaced, and there are no new laptops that you can coerce AppleCare into giving you. Apple has issued a statement extending the service period for the NVIDIA defect for another year. If you encounter distorted or scrambled video, no video at all, or uncharacteristic blemishes on your MacBook, you should take it in to the Apple Store.
    
The specific models that are affected are:

MacBook Pro 15-inch and 17-inch models with NVIDIA GeForce 8600M GT graphics processors
- MacBook Pro (17-Inch, 2.4GHz)
- MacBook Pro (15-Inch, 2.4/2.2GHz)
- MacBook Pro (Early 2008)

This is a major PR blow to Apple, who generally advertise the product line’s immunity to such problems. Lucky for them, the same faulty chips have affected several other computers made by Dell and HP, and the three companies have filed several individual lawsuits to recover some of the money spent on service. Kudos to Apple for at least addressing the issue instead of shirking responsibility.

The complete support document can be found here.