Borge Ousland and Mike Horn, two well known solo explorers, have joined forces and are currently attempting to complete a polar expedition to the North Pole during the Winter, when that area of the World is in complete darkness for 24 hours a day. It'll be the first time that such a trek was successful, should they complete the journey.
National Geographic has an excellent article laying out the background of the story. It's a great read to get you up to speed about these two men and what they are trying to do. Ousland and Horn began their adventure on January 15th, and have had slow progress since, due to finding thin ice, forcing them to backtrack, and find alternate routes.
You can follow the progress of the expedition on Ousland's website, Horn's website, or at The Poles.com.