Well, as the author points out sheepishly at the end of the article, he didn't even list 50 as nearly half of the businesses listed had previously used a domain that wasn't a .com. There were .net's, .org's, .org.uk's, .co's, obscure cctlds and domains with hyphens in...
So obviously if your old domain was a bag of shite then opting for a new gtld would be one way of improving it without incurring the cost of getting the equivalent .com. Not without problems though, not least with people remembering the domain wrongly. It will be interesting to see how many of these actually stick with the new gtld.
I wonder if there will be an article about 50 MILLION businesses who didn't give up their .com