Over on SaaS blogs, Sinclair posted an excellent discussion continuing the SaaS/OpenSource discussion.
As part of his post, Sinclair developed this model to describe the steps and routes from development to implementation;
You’ll see that we can trace multiple routes and mash up the way we develop, sell, deliver and use a software product.
None of the combinations are necessarily wrong however one thing that Sinclair, Bob and myself agree upon. As do, I suspect, the majority of people who can stand back and look at it from a dispassionate, user-centric viewpoint. That thing is embodied in the diagram below. The traditional software development and delivery model that is becoming rapidly irrelevant.
Bob and Sinclair posted comments discussing the fact that a community developed product is dependent on having a community of interested, committed and participatory individuals. Clearly a SaaS/OpenSource mashup is predicated on this community existing, or being able to be created.
Ben Kepes is an analyst, an entrepreneur, a commentator and a business adviser. His business interests include many industries from manufacturing and property to technology. 
Krishnan Subramanian is an entrepreneur, cloud computing analyst and consultant, open source researcher and evangelist, one of the industry’s most prolific bloggers. 