Apple, which doesn't usually comment of these sorts of matters, said to AllThingsD that the new iPad uses the same charging process as its other iOS devices.
Nothing new about the charging process
Apple went on to confirm that its charging process (which features in the iPad, iPhone and iPod) allows its devices to maintain optimum charge.
This is achieved by the device displaying 100 per cent charge when it's nearly fully charged, then it will continue to charge to actual 100 per cent, discharge a small amount, then recharge to 100 per cent and the process is repeated. Got all that? Good.
So what is being said here? Well Apple has admitted that yes, the new iPad technically does say it's 100 per cent charged before it actually is, but thanks to its fancy charging process you don't need to worry. Phew.