Hi, I just wanted to add my experience to this thread.
I was having the same issues as everyone else on a new iPad wifi only 64Gb. Tried all the solutions, switching off wifi, locations services, push email and even restoring back to factory setting with no apps installed, but was still getting the 7-9% drain overnight (roughly 8 hours).
I spoke to Apple phone support who were very helpful but basically said 1% drain per hour in standby was usual, so I was almost ready to give in and just put up with it as a 'feature' of the new iPad. Luckily a couple of days later I was able to compare against a friends new unit and as I expected, his had no drain in standby overnight.
As my 14 day guarantee was almost up, I decided to book a Genius call and after explaining the situation to the support guy (once again, who was very helpful) he was more than happy to swap the unit over.
I'm now the proud owner of the device I originally started out to buy - absolutely no drain in standby overnight, no heat issues or wifi problems - basically, really pleased with it.
The moral of the story is that although the 1% drain per hour maybe within tolerance (and could just possibly be mis-calibration on the battery meter) there are units out there that perform as I would expect out of the box.
My last comment would be praise for the Apple support - although it is annoying to get what I class as a defective unit, at least they can be bought with the knowledge that Apple will try their best to help the customer ultimately get the device they are after, even if that involves multiple swap-overs.
Hope this post is useful to someone.