"Today, a Falcon 9 rocket will launch from Space Launch Complex 40 (SLC-40), Cape Canaveral Air Force Station, Florida on the 6th SpaceX cargo resupply mission to the International Space Station (ISS). Yesterday, NASA held three news briefings to discuss the mission and research on the ISS."
Marc's note: At the briefing, SpaceX's Hans Koenigsmann was asked what the probability of success for the Falcon 9 first stage landing on the drone ship. His response was 75% and then he said perhaps 80%. It seems SpaceX is quite a bit more confident on this third attempt.
Marc's update: The launch was scrubbed until Tuesday at 4:10 pm EDT due to weather. The weather forecast for tomorrow is 50-50.