Matsushita, aka Panasonic, announced that a safer lithium-ion battery for laptops is now ready for mass-production. How is it safer? A heat-resistant insulator is added to the battery cell. It is meant to prevent overheating during a short circuit and therefore should prevent fires and explosions. The company has also proclaimed that "contaminating foreign substances" have been eliminated from battery materials which results in a clean environment for the battery factory. It is believed that Sony's exploding batteries were contaminated with small metal particles during the manufacturing process. New laptop battery standards targeting safety and reliability are on their way ( before 2008 ) from both the IEEE and the IPC.
News source: Ars Technica