Varies, depending on who you talk to. A number of people have stated it has gotten better, and quite a few have stated it is worse. For me, I have had both. Not sure why. After my "overnight" charge, it discharges fairly quickly, dropping to 35% in just 3 hours. After an additional charge, where I take it off the charger between 85% and 90%, it will last another 10 hours.
However, I generally spend the first part of the morning checking out and testing features of the preview, so it could just be that my usage is heavy enough to run it down.
This is on an AT&T Lumia 635.