How will the cloud affect current application architectures? This is more than just an academic question now that many enterprises, or rather enterprise employees, are rushing headlong into the cloud regardless of how management might be trying to control the situation.

On the one hand, there are those who say existing applications will have a very tough time in the cloud, considering they were never meant to run free in such a dynamic, open environment. At best, the mix could cause conflicts among cloud- and enterprise-based systems, hampering productivity. At worst, enterprises could lose control of data and workflows completely.

Computerworld’s Bernard Golden lists poor application migration as one of the chief reasons the cloud may not be ready for the enterprise just yet. His take is that since each of the major cloud providers uses a proprietary architecture that differs from the ones normally used for enterprise applications, getting internal apps out the door, let alone sharing them among providers, is more of a challenge than most people realize. Perhaps some sort of physical-to-cloud (P2C) migration tool might be in order?

It would be, argues Intelligent Enterprise’s David Linthicum, but only if you were interested porting internal apps onto the cloud. The fact is, though, the cloud is likely to spawn its own applications capable of handling the free-wheeling nature of the environment.

We’re already seeing this, says Simon Wheeldon, EMEA director of Force.com, the cloud-focused wing of Salesforce.com. In this podcast on ebizQ, he points out that the new platform-as-a-service (PaaS) offerings are free to developers, asking only a portion of the sale or subscription fees when the app is released. This essentially provides open access to the most tricked-out development systems and architectures on the planet, inviting a veritable flood of top-flight cloud applications over the next several years.

A prime example is the Cloud Tools project hosted on Google Code. It offers a complete toolkit for developing, testing and managing Java Enterprise Edition applications on Amazon’s Elastic Compute Cloud. A recent survey by Evans Data indicates 40 percent of open source developers are planning to deliver applications as Web services over the cloud.

The transition from one technology to another is always fraught with complications. For the early cloud adopters, the set of applications may not be up to the level of what users have become accustomed to on the enterprise, yet. But that should be tolerable, considering most people are just getting their feet wet. Only a fool rushes headlong onto thin ice, so while we’re all just starting up the cloud learning curve, it’s probably best to stick with the applications that are already optimized for the cloud and worry about migrating internal apps later. It may turn out that we won’t need to at all.