Interesting data points: only 8 of the 25 hold this exalted position both a decade ago and now. China's looming world dominance is indicated by corporations under its banner holding four spots now vs. none then. And the total market cap of the top 25 shrank by 20 percent.
creative destruction is one of the triumphs of the market. The consumer is king: in 2009, the consumer wants iPhones in their Xmas stocking and not whatever Worldcom had been pretending to be producing. The radical uncertainty of how to please consumers is an argument FOR free markets.
Anti-corporate types might respond: 100 percent of the richest corporations are and remain rich corporations, and they'd be right, as far as it goes. But for students of the specific exercise of "corporate power" by specific corporations, this is interesting stuff.