To date, cloud computing services have garnered more column inches than business customers. Enterprise buyers continue to harbour doubts about putting business-critical applications in the cloud, their chief concerns being security and availability.

But with industry heavyweight Microsoft recently unveiling its massively scalable cloud computing platform, Azure, IT leaders may take a closer look at cloud services.

Azure is due to go live some time in November, with services running from three massive datacentres, one in the US, one in Ireland and the third in Singapore. Further datacentres will be added in the first half of 2010.

Microsoft's Azure platform has three components: Windows Azure, which provides the compute function; a SQL Azure database component; and Azure.Net services, which glue the whole thing together. The prices for each component will vary, and Microsoft will offer various service level agreements.

Nevertheless, Microsoft has some significant barriers to overcome in persuading enterprise customers to move business-critical data outside of their firewalls, says Forrester information and knowledge management analyst Sheri McLeish, not least of which is the disruption it would cause to staff.

"Remember disrupting your workers is one thing you don’t want to do,” she says.

However, Microsoft has already attracted some early adopters, and hopes their experiences will encourage others.

One such early-adopter of Azure will be budget airline Easyjet, which is looking to move to a new departure control system (DCS), called Halo, which would allow it to mobilise a lot of the services that people currently have to queue for, such as baggage drops.

The airline's future plans for Halo might include moving more of its back-end data up into a SQL Azure cloud database, said Easyjet enterprise architect Bert Crave.

Elsewhere, the Royal National Lifeboat Institution (RNLI) is testing an Azure-based system featuring mobile devices that are designed to be worn by fishermen, which activate on immersion and alert RNLI crews via satellite that a person has fallen overboard.

One of the critical parts of any cloud computing service will be the pricing model, and Microsoft is to launch three purchasing options for the service initially: a "pay as you go and grow" option; a subscription-based model that gives discounts if firms make a specific commitment over time; and a volume licensing model similar to that used for Microsoft's enterprise software packages.

"Comparisons with other providers are never easy due to a range of factors, but Microsoft's basic compute unit is in the order of magnitude similar to that of Amazon, at least in terms of a headline figure of $0.12 vs. $0.10 on AWS EC2 [Amazon Web Service Elastic Cloud 2]," said Datamonitor principal analyst Vuk Trifkovic.

“While I don't believe that Azure users should wait for the prices to come down, I could potentially see an incremental drop in price at some point in the future,” he added.

While Azure takes software patching and hardware management out of firms' hands, a critical area for enterprises rolling out applications on Microsoft's platform will be how they monitor usage of resources and track application performance. Configuring an Azure application for optimal performance will require some sharp management tools.

Microsoft's product marketing director for cloud infrastructure services, Prashant Ketkar, says that it will provide application programming interfaces (APIs) that allow firms to use third-party management tools. This will also ensure the platform can co-exist with other cloud offerings.

"We’re totally committed to interoperability, and potentially you could have an application front-ended on Google’s app engine, with storage running on Azure – to the user the service would appear seamless," he said.

Not everyone shares his confidence. A recent report from analyst Gartner, Three Types of Cloud Brokerages Will Enhance Cloud Services, says that cloud services will be too complex and untrustworthy for firms to handle properly unless a ‘brokering service’ is used.

Gartner’s managing vice president and chief Gartner fellow, Daryl Plummer, said that using third-party cloud services and ensuring that they will work, not only separately, but also together, “are complicated tasks, rife with data integration issues, integrity problems and the need for relationship management. Hence the role of brokers to add value to services and to deliver new services built and delivered on top of old services.”