"There will be no changes to the center wing box, but the wing will be extended, twisted and strengthened to handle the 5 tons of additional weight."
Airbus: More Than 1,000 Orders Coming For A330neo | Commercial Aviation content from Aviation Week
"There are also some penalties to be counteracted: 1% because of increased drag (the fan diameter is increased to 112 from 97 in.) and 2% because of additional weight."