What are the the Top Issues Companies Face as Cloud Computing and SOA Converge?

The primary issue is understanding that one is architecture and the other is a business model for acquiring compute resources. Convergence occurs for these two entities when one is planning for delivery of services end-to-end. Hence, keep your Cloud Computing and SOA initiatives separate, but ensure your Cloud strategy supports your SOA strategy.

Looking at it from an SOA perspective, in the cloud a service will not be just restricted to an enterprise or its associates but would be used by a much larger audience; for that the issues that need to be taken care of are:
Service Governance Governance of Services is a key issue that needs to be dealt with. Right from provisioning, compliance to accepted standards, life cycle, service granularity as well as versions. It will get even more highlighted as the scale will be much larger and the presence of multiple organizations.
Look up Registry Consumers should be able to find services that are available which fits their bill and be able to use them. Here too due to the larger audience/varied consumer groups, ease of look-up will play an important role..
Security in my opinion it would be one of the most critical areas of concern. In a cloud one is not sure of the source from where a request is being serviced and with multiple organizations involved that could use a particular service it will have to be handled with much more care. And here we are talking about critical enterprise data which the enterprises would in no way want it to be compromised at any level.
SLAService Level Agreement will be another concern – if we look at the distributed nature of cloud computing SLAs need to be well calibrated within acceptable variances. The management of SLA would also be required. And further the involvement of multiple organizations – could be competitors! - would make security a key issue.
QoS Quality of Service would have to be well thought out and proper agreements would have to be made depending on the usage by various consumer groups/organizations as each will have different reasons for using a particular service.

Governance, governance, governance. We'll be seeing plenty of JBOCS (Just a Bunch of Cloud Services) all entangled through organizations, just as we have JBOWS. And JBOCS will really start eating into budgets in a big way.

I'm glad the question was asked this way as it brings up two threads.

1. What is meant behind the statement "cloud computing and SOA converging"? and

2. What does one imply to the other?

When I hear cloud computing and SOA coverging it's kind of like saying a rain storm and large surf are converging --both will impact my day on the beach and both may amplify the felt effects of the other but one does not take the place of the other. In my opinion, SOA is going to happen with or without cloud as it's an architectural approach that makes sense for certain infrastructure and application projects. Cloud is going to happen as it's a delivery style and business model for sourcing application, infrastructure and platform capabilities that also makes sense for certain projects. And, as it turns out, there are practices we can leverage from SOA and aspects of SOA that help in the development, delivery and management of cloud services. SOA has the potential to make the integration of existing data, infrastructure and applications with cloud services easier to intially implement and more change resilient. SOA also has the potential to help with on-going consumption of cloud services via governance and management. I completely agree with the previous posts that governance is absolutely critical when we offer services via the cloud.

Now I'm getting into the second point.. what does one imply to the other... It has always been a good thing to put in place a way to govern services in a SOA. Governance is proven to help with consistency in implementation, adoption of standards and best practices, visibility to reduce redundance and tracking and management of service use or consumption. Now, take this concept out to the cloud. Cloud providers may offer up their services to many different types of customer (consumers) under different sets of business and technical expecations. And, the impact of shades of compliance to these expectations may be minor inconvience or major revenue impacting results (loss of customers, legal implications, financial penalty, loss of brand credibility and so forth). Having in place a system of governance for all the different levels of consumption and the different aspects of service delivery objectives will be key to any cloud provider that wants to scale beyond the scope of Wysiwyg gadget provider.

A longwinded reply but this topic provides a lot of future food for thougth. Let's hear from those who cut their teeth on the first chapter -- ASP providers from the early 2000's.. what does SOA bring that makes this round of cloud service providers' life easier and potentially a more mature experience for customers?