I agree that this is a good first step.
A couple of years of history suggest that only those U.S. LEAF owners in the desert southwest, Texas, South Florida and Hawaii may see battery degradation which exceeds the new, proposed warranty, and even in those cases, they will have a guarantee to retain at least 70% capacity through 60,000 miles or five years, whichever comes first. Since those LEAF owners represent just a small fraction of the total LEAF owners in the U.S., it seems like a reasonable business decision on Nissan' part.
However, it doesn't change my view that LEAFs should be lease-only in hot climates (like the ones I mentioned above). And, if you are someone in a hot climate, who puts so many miles a year on a car that a lease isn't a viable choice, I'd skip the LEAF entirely.
2013 Crystal Red Volt
2012 SV Glacier Pearl LEAF; turned in 5/12/2015:18.6K Miles:50.13 AHr:10 bars, 24% gone