A rare decline in November sales, its first in a decade, last week landed Wal-Mart on the front page of The New York Times, under the headline “Wal-Mart Trips as it Changes a Bit Too Fast.” “The stumbles seem to resurrect the perennial question,” wrote Michael Barbaro, “Is Wal-Mart too big for its own good, making it impossible to achieve the gravity-defying growth that Wall Street has counted on for four decades?”