This is the famous Nvidia video card overheat debacle. Many laptop manufactures offer "secret" extended warranty -- nobody is officially claiming the responsibility. A total recall will put many companies in financial distress. But if it does happen and end users pushes for it, they will replace the motherboard for you for free. HP does that. Many people on HP forum reported that they were able to force HP service into free repair, after regular warranty expired. Apple offers refund toward a new Macbook. Toshiba/Sony always blames end user for not properly ventilating the laptop -- ridiculous, should end user dig a hole in laptop?
Lenovo should offer similar program, if they care about their reputation. Ask to speak to a manager there. This is a quality issue. They sold u a product that has hidden defect built in. Please threaten that you will take this issue up to consumer reports, BBB or even state attorney's office. Threaten to make this issue well publicized.
FYI. Take a look at these links.
http://forum.thinkpads.com/viewtopic.php?t=64393
http://www.gizmodo.com.au/2008/07/inquirer_every_nvidia_graphics_card_with_g84_or_g86_chipset_is_ready_to_die-2.html