Putting computing in the cloud promises huge cost savings to most American corporations, according to vendors of technology and cloud-related services at the first Bloomberg Enterprise Technology Summit in New York.

But the two-day collapse of Amazon Web Services last month is the kind of incident that underscores the concern that continues to keep critical applications, such as Wall Street's trading programs, out of remote, hosted online services and data centers, said Geoff Tudor, chief cloud strategist at Hewlett-Packard Company.

"You are going to continue to see concern about security,'' Tudor said. When it comes to the cloud, the constant hurdle to overcome in increasing the rate of adopting computing service hosted by a specialist is "security, security, security,'' he said.

You can't walk through a data center at Amazon, he noted, and check to see what's working or not. For now, companies will move non-real-time data analytics and other non-mission critical applications into the cloud. But not the most meaningful ones.

That split between non-critical and critical apps means that the rate of adoption of cloud services is overtyped, said David King, chief technology officer at Logica, a cloud technology firm.

The "vast majority" of companies still have not, for instance, virtualized their desktop computers, said Arthur W. Coviello, Jr., executive vice president, of storage supplier EMC Corporation.

Splitting up computing power on remotely located servers into "virtual" desktop machines whose workings are indistinguishable from conventional desktop computers actually sitting on or under a desktop is one of the signature features of cloud computing architecture.