The data could be lost. Part of DiRT is ensuring that the result of losing N data centers is not "oops we lost 20% of GMail users data permanently".
On the scale of devastation this article is describing, none of Google's servicing being obliterated really matters but I'm personally pretty glad Google is prepared for multiple, massive scale disasters to happen at once.
The financial disaster would be horrendous. Look at the number of companies using google for email.
When the towers went down in 2001, the first business priority of many companies was getting email back online. It's an incredibly important part of a business.
Reminds me of when I was doing some consultancy for large oil/energy trading company in London. There was huge DR initiative going on at the time, and one thing they realized after surveying the business is that, if worst came to worst, they could still conduct business if they lost every other business system, as long as e-mail was available.
On the scale of devastation this article is describing, none of Google's servicing being obliterated really matters but I'm personally pretty glad Google is prepared for multiple, massive scale disasters to happen at once.