There's an issue with the Leaf which has been bubbling for a few months - you can find lots of discussion over on the MyNissanLeaf discussion board. I've been covering the issue with news reports and thought it would be good to summarize the coverage.
Basically.. The owners understood Nissan to promise 80% remaining capacity after 5 years. However, many Leaf owners are suffering from a high rate of capacity loss that in some cases they already are down to 80% or others will be down to 80% earlier than five years out.
This video is the clearest description yet from Nissan of the actual technical problem. Nissan has been cadgey and in damage control mode for months. This is a pretty straight-forward description, though it did take some careful listening to tease apart what he said.
As a related issue - Chelsea Sexton forming Advisory Board to help Nissan learn how to market the Leaf - Nissan and Sexton are working on an "Advisory Board" to help represent Leaf Owner needs to Nissan.
Nissan buys back two Leaf's under Arizona Lemon Law - The title pretty much says it ..
Nissan answers questions about optimally charging the Nissan Leaf This was a video from last Spring in which Nissan said you could quick charge the Leaf as often as you like. It directly contradicts what Andy Palmer said in the video from a couple days ago.
Nissan responds to Leaf owners worries about battery capacity loss
Nissan publishes open letter to Leaf owners over battery capacity loss
Nissan responds to Leaf owners' massive test in battery aging case
As the controversy unfolded, Nissan made several attempts to explain. As I said above they weren't very good explanations and did more to get people angry than anything.
In wake of Leaf battery flap, Coda points to active thermal management - One of the issues is heat - that the battery packs get hot, degrades the lifetime. Nissan uses passive air cooled batteries. Coda uses an active air conditioning system to keep the packs cool.