The biggest challenge for enterprises will be management, according to IBM, in particular the proliferation of virtual machines and software images. It hopes to distinguish itself from other cloud providers by the level of security and management it says it can offer.

"We see the proliferation of images happening at a rate that makes the proliferation of Intel machines look like it was happening in slow motion," said Robert LeBlanc, IBM senior vice president for middleware.

IBM officials played down the suggestion that they will be competing more directly with partners, such as telecommunications providers, who have been offering their own cloud software based on IBM software. Such "coopetition" is normal in the industry, Mills said.

Although ING isn't using a public cloud, it is deploying "utility" applications such as social media tools on a private cloud, Kerrison said. It has a mix of x86 and IBM Power systems, and the company uses IBM's Tivoli software to abstract the hardware underneath and manage all the servers "at a higher level," he said.

The ITIL best practices for IT are geared towards physical infrastructure, Kerrison noted, so ING has developed its own processes to ensure software stacks in its cloud are as standardized as possible. That makes them easier to manage, and also helps with software development lifecycles, he said: "Developers are clear when new stack releases are coming out. We treat our stacks really like a software release," he said.