I agree that it would have to be something very adaptable to usage with cloud-based approached...still, even where I work (Oklahoma) we're on a tornado-prone area, and I work for a small "State and Local" government agency. We considered moving our datacenter to a location that is rated for EF5, flood proof, redundant this and that, and would safehouse our data entirely from any imaginable threat except nuclear. The costs were reasonable as well for what we'd co-locate...but what killed it was the need for bandwidth. Given our funding situation (current backlash against government spending, and my employer is a common target it seems for spending cutbacks) - having that additional cost per-month to have a live-failover location wasn't going to work for us. In the end, we did nothing about it...just we make sure our backups are good and send those off to an EF5 rated location...as we have for decades.
Basically, what I'm saying is the same thing - that if your business model is such that having something like this in place, where it can be done, great, but, I imagine that there is a large customer-base that it's just not applicable. I fear that Amazon (and others) are taking a bit more of a "build it and they will come" approach, vs watching what the market will do and sustain. Right now, it's a buzzword...just like IPO and Web Site and Internet were a buzzwords in the 90's.