Others were less convinced. Ron Croce, the COO at data center infrastructure provider Validus DC Systems, said Microsoft and Google are unique in their requirements. Microsoft's online services are mostly Web-based applications running on x86 servers, he said, and don't need the level of uptime and security as firms in, say, the financial services sector.

Building traditional data centers may not be cost-effective for Microsoft, but for other companies it's still a necessity, he said. "A lot of the requirements are driven by regulatory mandates. If you're a financial services company, you can't have a data center with no roof."

"It's certainly a valid concept but I don't see it as suitable for everyone," said Christopher Johnston, vice president of critical facilities at Syska Hennessy Group. "I think people will have to make a judgment depending on the type of industry they are in."