Where is the Killer App for PaaS?

Over the last month, I have had lengthy discussions about developer adoption of Platform as a Service with two of my favorite cloud computing analysts - John Rymer of Forrester and Michael Cote of RedMonk.

The net of these conversations that we are still early in the adoption curve for PaaS. In particular, developers are not yet demanding PaaS the way operations people are demanding Virtualization.

Here is my summary of these discussion:

• Developers are wary of PaaS: developers are not overly keen on PaaS at the moment. They are not yet mentally prepared to give up the middleware layer of their applications. Lacking a compelling reason to use PaaS, developers are sticking with tried and try development stacks.
• PaaS for existing apps has limited benefit: For existing applications, there's not much to gain by simply moving from non-cloud modes to cloud modes. This is the foundation of Cote's Cloud Rule - "if it ain't broke, don't cloud it".
• PaaS fits best for new apps: with new applications, the benefits of PaaS (cost and agility) all seem to line up.

This means that cloud vendors need to "connect the dots" for developers and business managers to accelerate their adoption of cloud platforms. In particular, there are two

• PaaS lowers the bar for web development: PaaS solutions like Cloud Foundry and WaveMaker make the cloud's benefits available to everyone, not just the A-Team. Of course, this requires significant education to let business developers know that easier web dev tools exist.
• PaaS speeds the delivery of apps for all developers: Michael Cote recently argued that speed is the killer app for cloud. Again, this requires market education to get the word out that quantifies these benefits.