It's not terribly rare that a stock splits in the Dow.
The index value itself doesn't change on account of the split (that would be ridiculous). Visa's weight will drop, and every other stock in the index will increase accordingly. They use an index divisor to maintain the current level of the index when corporate actions like this occur: http://www.investopedia.com/terms/i/indexdivisor.asp
At this point, the Dow is only cited because "it's been around forever." That, and Dow Jones is owned by News Corp. So of course the media wants to keep promoting its own subsidiary.
The one thing the article fails to mention is that the addition of Apple will coincide with a 4:1 stock split in Visa[0]- the index's highest priced (and thus highest-weighted) holding.
Although the addition of Apple had been anticipated, Visa's split was definitely a catalyst. Had they not added Apple, the technology sector within the index would have dropped significantly, in line with Visa's split. The addition of Apple will minimize the impact.
The index value itself doesn't change on account of the split (that would be ridiculous). Visa's weight will drop, and every other stock in the index will increase accordingly. They use an index divisor to maintain the current level of the index when corporate actions like this occur: http://www.investopedia.com/terms/i/indexdivisor.asp
At this point, the Dow is only cited because "it's been around forever." That, and Dow Jones is owned by News Corp. So of course the media wants to keep promoting its own subsidiary.