Like most commentators, the Daily Telegraph's Jenny McCartney is taken by the word and wants to use it more herself. However, she doesn't have the right meaning, at least to my ear. I know the word from sports broadcasts, but also (I think) from old war movies.
When you give the enemy a good "shellacking" you're not just winning, you're pounding him - hard, so he begs for mercy. You can't use the word (again, to my ear) as McCartney wants to, describing her malfunctioning computer as "completely shellacked" or to describing yourself as "shellacked by the flu."