I agree that for companies that take the E 2.0 plunge, Open Source has by far the greatest upside. Your point that buying a solution, especially from a big vendor, is somewhat like taking out an insurance policy to make sure that you will have viable long term solution.

What I really wanted to stress was that with Open Source solutions organizations need to realize they become part of a collaborative community that runs on reciprocal sharing. IBM has invested extensively in the LINUX platform and benefited from the open source system, but the organization has also released hundreds of millions of dollars of innovations back into the community. Organizations who choose open source E 2.0 solutions need to be prepared to do the same thing.

Open Source solutions can, and are used to bootstrap self built systems, avoiding pitfalls that other companies have already experienced, and reducing the total cost to build.

Open Source solutions are generally easier to migrate from, so they also provide excellent proving grounds, alowing an organisation to learn the solution space to then move towards systems that support their business.

And lastly, open source solutions benifit from the possiblility that any suitably qualified person could learn to fully support it – unlike most bought systems.

So the 3 options could be re-categorised as:

Build (a totally new system) – if you already know more about Enterprise 2.0 systems than anyone, and are confident you can avoid the pitfalls other systems have already recovered from.

Buy – if you already know the detailed impacts of the different solutions that exist, and are certain that the software in question is not only the best solution for today, but the best solution for your unknown needs in 5 years.

Open Source – if you want to hedge your bets, and be able to take your Enterprise to unimagined heights.