Just noticed two reports on the ZDnet and BBC saying that NAB was going to have to write down $1 billion! roughly 20% below expectations.

NAB takes AU$1b hit, writes down AU$297m in software
NAB takes AU$1b hit, writes down AU$297m in software | ZDNet

National Australia Bank earnings hit by UK charges
BBC News - National Australia Bank earnings hit by UK charges

Not sure if the software and US deferred tax will be included in the 1 billion dollars right down?

NAB software write down:
NAB also announced an AU$297 million impairment linked to capitalised software, mostly within its Australian business.
The bank said the benefits linked to the software had been substantially below what was expected.
"Where the benefits associated with the software were substantially reduced from what had originally been anticipated, the costs of development are in excess of expectations, or there is uncertainty when the technology capability will be deployed, the software has been written down to its recoverable amount," the company said in its statement to the Australian Securities Exchange.
"Included within the above impairment charge is AU$106 million (AU$74 million after tax) for certain assets related to the NextGen capitalised software balance, other than the core banking platform asset where no impairment is required. This represents approximately 10 percent of the total NextGen capitalised software balance."

US deferred tax assets:

It will also take a $120 million hit relating to deferred tax assets in the US, while a reduction in tax offsets linked to research and development will reduce full-year cash earnings by a net AU$28 million, after tax.