I recently attended a dot-com launch. What was unique about this particular launch was that the company does not own any servers, and they do not have a data center or even rack space in a co-location facility! Instead they run on virtual servers controlled with a Web service interface, and store their data “in the cloud” using a Web service.

Virtualization is almost a cliché in 2007. IDC lowered its server revenue forecast as a direct result of virtualization. Especially because IDC’s report missed the new phenomenon known as “Web Scale Computing”.

Service-oriented architectures offer many important advantages to the enterprise in terms of agility, flexibility, consistency, reuse, integration and others. But of course, there’s no free lunch. And one of the costs of these advantages is the increase complexity of service lifecycle management and versioning.

Once a service has its first consumer, we have bought off on having to maintain and support that service for an agreed upon period of time.

Clearly, SOA and SaaS are converging. The movement and direction are clear. Take, for instance, the rapid rise of SaaS.  Based upon current trends, IDC predicts a compound growth rate of 20% per annum for SaaS, set against the overall software market, which is only growing at around 6% per annum.  This leaves IDC in no doubt that there is a fundamental shift toward SaaS as a delivery mechanism, and its use within the notion of Web 2.0, and the convergence of SOA, Web 2.0, and SaaS.

What’s causing this shift?  There are 5 primary drivers:

1. Purchasers believe th