4. Containers are a temporary, not long-term, solution

To meet its opening date for the Chicago data center, Microsoft has already opened the containers up for bid. Manos declined to comment on which vendors are in the running, but he confirmed that Microsoft hopes to award contracts to multiple vendors.

Microsoft is in the midst of its huge data center expansion in order to accommodate its growing Windows Live and Office Live online services. As a result, containers provide an "excellent opportunity to increase the scale unit, from server, to rack, to server to mini data center," Manos said.

But what happens when expansion inevitably slows? Eventually, adding servers one 2,000-server container at a time will start to feel like going to Costco to buy a 50-pound bag of dog food for your toy poodle.

"I think this is a very short-lived, ephemeral model that may work right now," said Biggs, who added that most data centers operators, such as Peak10, have no interest in containers because the scale is simply too large for them and their customers.

"The only thing interesting to me about containers is the predictability of how much power you need and how much heat you'll produce," he said. "Otherwise, they're kind of a novelty."

That's why some observers, such as Ohara, say the market is actually in smaller units. A former supply chain engineer for both Hewlett-Packard and Apple, Ohara has been developing his own prototypes for a "server cube" that would weigh about 1,000 pounds and measure 1 meter in each dimension -- hence the name of his blog, GreenM3.

"It's taking what's in a server rack but putting it into a cube to make it more efficient to roll out," he said. "That potentially could apply to many more people."

Manos agreed that containers aren't the be-all and end-all for data centers, including Microsoft's. He pointed out that the second floor of the Chicago data center will still be fully comprised of conventional free-standing server racks.

"For us, it is about right-sizing the scale with the 'needs and speeds' of deployments," he said. "As it stands today, containers deliver on this goal."

"If trends continue as anticipated, containers will continue to be an important piece to the puzzle, but not the only piece," he said. But Manos also acknowledged, "The only true constant in technology is that technology will change. Whether that means the server compute form factor changes I can only guess."